The ratio of girls to boys is 3 to 4. if there are 48 boys, how many girls are there?

48/4 = 12

12 * 4 = 48

12 * 3 = 36

There are 36 girls.

ANSWER:  

There are 36 girls in a class when there are 48 boys

SOLUTION:

Given, ratio of number of girls to number of boys is 3 to 4.

Ratio proportion for above condition is given as

Number of girls : Number of boys : : 3 : 4

Ratio proportion can also be written as   --- eqn 1

Now, given that, find how many girls, when there are 48 boys in the class.

From eqn 1 we have  

No. of girls = 36.

Hence, there are 36 girls in a class when there are 48 boys

the revenue of the fitness center, y, is the product of two factors: the number of members and the fee paid by each member. there are 320 members now, but number of members goes down by 10 for each $5 increase in fees, so if x is the number of $5 price increases then members is equal to (320 - 10x). since the fee is currently $45, and the fee increases by $5 for every price bump x, the fee is given by (45 + 5x). so, revenue y is given by y = (320 - 10x)(45 + 5x).