# There are 6 times as many dogs as cats. If the total number of dogs and cats is 21 how many dogs are there?

$18$
There is $1$ cat for every $6$ dogs. So that is $7$ animals in $1$ "set".
We have $\frac{21}{7}$ "sets", which means $3$ sets.
$6$ dogs per "set" and $3$ "sets" means there are $6 \times 3$ or $18$ dogs.