Question

a pet shop shells dogs and birds there are 30 animals in all if there are 86 legs in all how many dogs and birds are there

Answer 1

let the total number of dogs be x
and the total number of birds be y
then according to question x+y=30(equation i)
as we know that dogs have 4 legs and birds have 2 legs=
total number of legs will be :
4x+2y=86 (equation ii)
(according to equation i ) x=30-y
120-4y+2y =86 (by equation i and ii)
2y=34
y=17
therefore x =30-y =13
so there are 13 dogs and 17 birds