In a herd of cattle, the ratio of the number
of bulls to cows is 1:6.
Find the number of bulls in terms of x.

In a herd no. of Cattle are: x

The ratio of bulls to cows is 1:6

\frac{bulls}{cows}  =  \frac{1}{6}  

6 bulls = 1 cows

bulls \:  + cows = x

bulls + 6 \: bulls \:  = x

7bulls = x