There are 6 times as many dogs as cats. Then there are 18 dogs
Solution:
Let the number of cats be "a"
The number of dogs is 6 times more than the number of cats
Then number of dogs is 6a
Total number of dogs and cats = 21
Hence we can say,
a + 6a = 21
7a = 21
a = 3
Hence there 3 cats and number of dogs is 6a = 6 x 3 = 18
Hence there are 18 dogs