The Robinson's have quite a lot of family pets. They have 3 times as many budgies as they have cats and there are a total of 30 legs between them.

Complete the following statement.

The Robinson's have
____cats and
____budgies.

I need help, can someone show me the working out so i can answer similar questions

Cats have 4 legs.

Budgies have 2 legs.
Two ways to do it:
1. use algebra.
C=no. of cats
3C=number of budgies
total number of legs
4(C)+2(3C)=30
10C=30
C=30/10=3
So 3 cats and 9 budgies.
Check:
3*4+9*2=30, checks.

2. by guessing
We don't know how many of each, make a guess, say 2 cats, then there are 30-2*4=22 legs left for 11 budgies.
We know that 2 budgies have as many legs as one cat, so change 2 budgies for a cat, or
11-2=9 budgies, 2+1=3 cats.
Since 9/3=3 times as many budgies as cats, we have 9 budgies and 3 cats.