Playbook
Ratio, Proportion and Variation
76 q · 9% HARD · about 3.6 a paper. Ratio and proportion and variation have no HARD at all; partnership and mixtures carry the little there is.
- Questions in the bank
- 76
- q/paper (21 papers)
- 3.62
- Tagged HARD
- 9%
- Subtopics
- 6
Strand: Quick-Win
When you’ll see it
Quantities shared in a ratio, incomes and savings, variation, partnership or mixing two things.
How this chapter is tested
76 questions, about 3.6 a paper, at 9% HARD. Ratio and proportion and direct and inverse variation have never set a HARD question; partnership and mixtures carry what little there is.
Almost every question falls to one move: write each quantity as a multiple of one unknown k.
The sub-skills
The distinct skills inside the chapter, in the order to learn them.
Sharing in a ratio
A sum in the ratio a : b : c gives shares a/(a+b+c) of the total.
Ratios in stories
Incomes, expenditures and savings, or ages before and after.
Equal ratios
If a/b = c/d = k, write a = bk, c = dk.
Variation
x varies as y: x = ky; inversely: xy = k.
Alligation
Two mixtures at prices a and b make price m in the ratio (b − m) : (m − a).
Traps to expect
Distractor shapes this chapter reuses. The Traps page covers the ones that cut across chapters.
Ratio after a change
Adding the same number to both terms changes the ratio.
Partnership by time
Profit is shared in the ratio of capital × time, not capital alone.
Learn it before you drill it
This chapter has full teaching notes — foundations, worked examples, self-checks and a mastery check for each subtopic. Read the notes once, then drill subtopic by subtopic below.
Ratio, Proportion and Variation notesDrill every Ratio, Proportion and Variation question
76 questions from the bank, across 6 subtopics.
Drill one subtopic at a time
The 6 subtopics, in teaching order.
- Ratio and ProportionDrill Ratio and Proportion
- Ratios in Income, Savings and AgesDrill Ratios in Income, Savings and Ages
- Equal Ratios and Proportion AlgebraDrill Equal Ratios and Proportion Algebra
- Direct and Inverse VariationDrill Direct and Inverse Variation
- PartnershipDrill Partnership
- Mixtures and AlligationDrill Mixtures and Alligation
Related playbooks
Often paired with this one — the technique or the trap overlaps. Drill these next.