Question

A farmhouse shelters 7 animals. Some are horses and some are ducks. Altogether there are 20 legs. How many of each animal are there?

Answer 1

3 horses and 4 ducks

Explanation:

let h be the no. of horses and d be the no. of ducks

h+d=7

d=7-h

Since horses have 4 legs and ducks have 2 legs,

4h+2d=20

4h+2(7-h)=20

4h+14-2h=20

2h=6

h=3

d=4