Posted by lisa on .
if the ratio of boys to girls is 3/4 and there are 49 students how many boys are there?

math 
Ms. Sue,
3/7 = x/49
Cross multiply and solve for x. 
math 
lisa,
75

math 
Ms. Sue,
Does 75 make sense? There are only a total of 49 students.
This site explains how to solve a problem with a proportion.
http://www.aaamath.com/ratpropcrossx.htm 
math 
x,
21