CDS (I) 2020, Elementary Mathematics question paper
100 questions · 100 marks · 120 minutes · +1 per correct answer, -0.33 per wrong one
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- 1The number is
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- 2Two unequal pairs of numbers satisfy the following conditions : (i) The product of the two numbers in each pair is 2160 (ii) The HCF of the two numbers in each pair is 12. If is the mean of the numbers in the first pair and is the mean of the numbers in the second pair, then what is the mean of and ?
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- 3How many digits are there in ? (Given that and )
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- 4Which one of the following is a set of solutions of the equation , if is a positive integer ?
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- 5In a competitive examination, 250 students have registered. Out of these, 50 students have registered for Physics, 75 students for Mathematics and 35 students for both Mathematics and Physics. What is the number of students who have registered neither for Physics nor for Mathematics ?
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- 6If the sum of the digits of a number , where is a natural number, is equal to 3798, then what is the value of ?
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- 7Which one of the following is the largest number among , , , ?
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- 8If is the number of prime numbers between 0 and 50; and is the number of prime numbers between 50 and 100, then what is equal to ?
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- 9If , , , and , then what is the value of ?
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- 10Which one of the following is the largest divisor of , if is any natural number ?
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- 11A two-digit number is 9 more than four times of the number obtained by interchanging its digits. If the product of digits in the two-digit number is 8, then what is the number ?
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- 12If and are the roots of the quadratic equation such that , then what is the positive value of ?
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- 13What are the values of and respectively, if and divide the polynomial ?
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- 14If is the HCF of and , then what is the value of ?
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- 15If , then what is the value of ?
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- 16A number divides 12288, 28200 and 44333 so as to leave the same remainder in each case. What is that number ?
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- 17If , then what is equal to ?
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- 18If and are positive integers such that , then what is the value of ?
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- 19What is equal to ?
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- 20If , and , then which one of the following is correct ?
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- 21If and , then what is equal to ?
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- 22If is divided by where , then what is the remainder ?
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- 23If the area of a square is , then what is its side length ?
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- 24If varies as , then varies inversely as
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- 25If the points and represent real numbers and on the number line, then what is the distance between and ?
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- 26What is the point on the -plane satisfying and ?
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- 27The price of an article increases by 20% every year and price of article increases by 10% every year. In the year 2010, the price of article was Rs. 5000 and price of article was Rs. 2000. In which year the difference in their prices exceeded Rs. 5000 for the first time ?
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- 28The ratio of speeds of and is . If allows a start of 70 m in a 1.2 km race, then who will win the race and by what distance ?
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- 29A train takes two hours less for a journey of 300 km if its speed is increased by 5 km/hr from its usual speed. What is its usual speed ?
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- 30If 6 men and 8 women can do a piece of work in 10 days; and 13 men and 24 women can do the same work in 4 days, then what is the ratio of daily work done by a man to that of a woman ?
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- 31Students of a class are made to sit in rows of equal number of chairs. If number of students is increased by 2 in each row, then the number of rows decreases by 3. If number of students is increased by 4 in each row, then the number of rows decreases by 5. What is the number of students in the class ?
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- 32A sum was put at simple interest at certain rate for 2 years. Had it been put at 1% higher rate of interest, it would have fetched Rs. 24 more. What is the sum ?
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- 33The population of two villages is 1525 and 2600 respectively. If the ratio of male to female population in the first village is and the ratio of male to female population in the second village is , then what is the ratio of male to female population of these two villages taken together ?
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- 34In a class room the ratio of number of girls to that of boys is . The average height of students in the class is 4.6 feet. If the average height of the boys in the class is 4.8 feet, then what is the average height of the girls in the class ?
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- 35What is the median of the data 3, 5, 9, 4, 6, 11, 18 ?
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- 36In a pi-diagram there are three sectors. If the ratio of the angles of the sectors is , then what is the angle of the largest sector ?
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- 37The maximum marks in a Test are converted from 250 to 50 for the purpose of an Internal Assessment. The highest marks scored were 170 and lowest marks were 70. What is the difference between the maximum and minimum marks scored in the Internal Assessment ?
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- Directions for the following three (03) items : Read the following information and answer the three items that follow : The following data presents count of released convicts who have served prison terms , those who have received some educational or technical training during their term and those who were offered Company placement respectively, from six different jails A, B, C, D, E and F, in the year 2010.
A 86 45 25 B 1305 903 461 C 2019 940 474 D 1166 869 416 E 954 544 254 F 1198 464 174 38Jails with highest and smallest percentage of trained convicts are respectivelyTap an option to check your answer.
- 39Jail with highest placement rate of trained convicts is
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- 40Jails from which more than half of the trained convicts are offered jobs, are
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- 41The number of three digit numbers (all digits are different) which are divisible by 7 and also divisible by 7 on reversing the order of the digits, is
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- 42How many integral values of and satisfy the equation , where and ?
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- 43Let be a 3-digit number. Let . Which of the following statements is/are correct? 1. is always divisible by 3 and 2. is always divisible by 9 3. is always divisible by 37 Select the correct answer using the code given below:
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- 44In covering certain distance, the average speeds of and are in the ratio . If takes 45 minutes more than to reach the destination, then what is the time taken by to reach the destination?
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- 45For two observations, the sum is and product is . What is the harmonic mean of these two observations?
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- 46If the annual income of is 20% more than that of , then the income of is less than that of by %. What is the value of ?
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- 47What is the least perfect square which is divisible by 3, 4, 5, 6 and 7?
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- 48In a water tank there are two outlets. It takes 20 minutes to empty the tank if both the outlets are opened. If the first outlet is opened, the tank is emptied in 30 minutes. What is the time taken to empty the tank by second outlet?
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- 49If is a factor of , then which one of the following is correct?
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- 50If , what is the value of ?
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- 51A wheel makes 360 revolutions in one minute. What is the number of radians it turns in one second?
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- 52What is the least value of ?
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- 53Let and . If , then which one of the following is correct?
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- 54If , where , then what is the value of ?
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- 55A tree of height 15 m is broken by wind in such a way that its top touches the ground and makes an angle with the ground. What is the height from the ground to the point where tree is broken?
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- 56On a plane area there are two vertical towers separated by 100 feet apart. The shorter tower is 40 feet tall. A pole of length 6 feet stands on the line joining the base of two towers so that the tip of the towers and tip of the pole are also on the same line. If the distance of the pole from the shorter tower is 75 feet, then what is the height of the taller tower (approximately)?
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- 57The angles of elevation of the top of a tower from two points at distances and from the base and on the same straight line are and respectively. What is the height of the tower?
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- 58What is the value of ?
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- 59What is equal to?
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- 60What is equal to ?
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- 61What is equal to ?
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- 62What is equal to ?
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- 63If lies in the first quadrant and , then what is the value of ?
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- 64What is the value of equal to ?
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- 65A rectangle is 48 cm long and 14 cm wide. If the diagonal makes an angle with the longer side, then what is equal to ?
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- 66What is the area of the triangle having side lengths , , ?
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- 67If the angles of a triangle are and and the included side is cm, then what is the area of the triangle ?
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- 68is a plate in the shape of a parallelogram. is the line parallel to and passing through the point of intersection of the diagonals and . Further, lies on and lies on . The triangular portion is cut out from the plate . What is the ratio of area of remaining portion of the plate to the whole ?
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- 69Two circles of radii 20 cm and 16 cm intersect and the length of common chord is 24 cm. If is the distance between their centres, then which one of the following is correct ?
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- 70In a circle of radius 5 cm, and are two chords such that cm. What is the length of chord ?
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- 71Two circles touch internally. The sum of their areas is cm and distance between their centres is 4 cm. What are the radii of the circles ?
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- 72If area of a circle and a square are same, then what is the ratio of their perimeters ?
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- 73A circle of diameter 8 cm is placed in such a manner that it touches two perpendicular lines. Then another smaller circle is placed in the gap such that it touches the lines and the circle. What is the diameter of the smaller circle ?
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- 74The thickness of a cylinder is 1 foot, the inner radius of the cylinder is 3 feet and height is 7 feet. To paint the inner surface it requires one litre of a particular colour. How much quantity of the same colour is required to paint all the surfaces of the cylinder ?
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- 75A square and a rectangle have equal areas. If one side of the rectangle is of length numerically equal to the square of the length of the side of the square then the other side of the rectangle is
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- 76The length and breadth of a rectangle are in the ratio . Then what is the ratio of the area of the triangle formed by the parts of the diagonals with a long side to the area of the triangle formed by the parts of diagonals with a short side ?
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- 77Suppose a region is formed by removing a sector of from a circular region of radius 30 feet. What is the area of this new region ?
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- 78is a parallelogram where and are the diagonals. If , , then what is equal to ?
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- 79A line through the vertex of a parallelogram meets in and produced in . If is the mid-point of , then which of the following is/are correct ? 1. Area of is equal to that of 2. Area of is equal to twice that of Select the correct answer using the code given below :
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- 80How many cubic metre of earth is to be dug out to dig a well of radius m and depth 5 m ?
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- 81If the diagonals of a rhombus are and , then what is its area ?
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- 82The lengths of sides of a triangle are , where . If one of the angles is , then what are the minimum integral values of respectively ?
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- 83What is the maximum number of circum-circles that a triangle can have ?
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- 84If an arc of a circle of radius 6 cm subtends a central angle measuring , then which one of the following is an approximate length of the arc ?
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- 85A ladder 5 m long is placed in a room so as to reach a point m high on a wall and on turning the ladder over to the opposite side of the wall without moving the base, it reaches a point m high. What is the breadth of the room ?
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- 86What is the area of the largest square plate cut from a circular disk of radius one unit ?
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- 87Out of 4 identical balls of radius , 3 balls are placed on a plane such that each ball touches the other two balls. The ball is placed on them such that this ball touches all the three balls. What is the distance of centre of ball from the plane ?
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- 88A right circular cylinder just encloses a sphere. If is the surface area of the sphere and is the curved surface area of the cylinder, then which one of the following is correct ?
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- 89is a quadrilateral such that units, units and . What is the approximate area of the quadrilateral ?
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- 90Let be the diameter of a circle of radius 9 cm. The length , and are equal. Semi-circle is drawn with as diameter (as shown in the given figure). What is the ratio of the shaded region to that of the unshaded region ?
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- 91What is the area of the shaded region in the given figure, if the radius of each of the circles is 2 cm ?
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- 92In the given figure, what is the area of the shaded region ?
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- 93In the given figure, if and , then what is the value of ?
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- 94is a trapezium, where is parallel to . If cm, cm, cm and cm, then what is the area of the trapezium ?
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- 95Angles are shown in the given figure. What is value of ?
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- 96In the given figure is parallel to , , , and . Then what is the value of ?
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- 97In the given figure is parallel to and is parallel to . If , , , then what is the value of ?
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- 98In the given figure, there are three semi circles , and . The distance between and is 28 units and is the mid-point of . What is the total area of the three semi circles?
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- 99What is the approximate area of the shaded region in the figure given?
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- 100Consider the following statements with reference to the given figure: 1. The sum of the areas of and is equal to the sum of the areas of and . 2. 3. Which of the above statements are correct?
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