6 times as many dogs as cats. Total number of dogs and cats is 21. How many dogs are there

Question

Please help me solve 

Answer 1

Aneisa, let's do this simply and with an equation. First, we need two numbers that fit the bill.

 

1 cat and 6 dogs? Noooo.

2 and 12? Still no.

3 and 18? There ya go.

 

d = 6c

c + d = 21

 

Since d = 6c, we can substitute...

 

c + 6c = 21

7c = 21

c = 3

 

3 + d = 21

d = 18