Heads and legs of two- and four-legged animals: number of four-legged ones

This type of question, asked 2 times: 3 Mar 2023 Tier II, 26 Oct 2023 Tier II. All 2 questions below, oldest first.

Try each one first, then open its answer.

Question 1
3 Mar 2023 Tier II
15 $Rewa has some hens and some goats. If the total number of animal heads is 100 and the total number of animal feet is 348, then what is the total number of goats with Rewa?$
Tap an option to check your answer.
Question 2
26 Oct 2023 Tier II
14 $At a certain time in a park, the number of heads and the number of legs of monkeys and human visitors were counted, and it was found that there were 54 heads and 148 legs. Find the number of monkeys in the park.$
Tap an option to check your answer.

Question 1