Question

A Group of some boys and Dogs have 7 heads and 20 legs. how many boys and dogs are there.

Answer 1

boys have 1 head and 2 legs.
dogs have 1 head and 4 legs.
let no of boys be x and no ofdogs be y.
so, x+y = 7; 2x +4y = 20
by solving this, we get x=4 and y=3

Answer 2

Boys have 1 head and two legs.Dogs have one head and four legs. So 4 boys have 4 heads and 8 legs and 3 dogs have 3 heads and 12 legs.So 4 boys and 3 dogs will have 7 heads and (4x2=8 and 3x 4=12) 20 legs.