Answer:
27 boys
Step-by-step explanation:
The ratio of boys to girls is 3 to 6. The total is (3+6) is 9.
Using the ratio of boys to total (3 to 9), we set it equal to the ratio of boys to total students (81)
3 b
---- = -------------
9 81
We can solve this using cross products.
3*81 = 9b
243 = 9b
Divide each side by 9
243/9 =9b/9
27 =b
There are 27 boys
