Carcass wrote:
The ratio of girls to boys in a class is 6: 7. If there are 18 girls, how many total students are in the class?
A. 18
B. 21
C. 27
D. 28
E. 39
We can solve this by using
equivalent ratiosWe're comparing the ratios of
girls/
boysLet
B = the corresponding number of BOYS
We get:
6/
7 =
18/
BCross multiply to get: 6B = (18)(7)
Divide both sides by 6 to get: B = (3)(7) = 21
So, there are 21 BOYS in the class (and 18 GIRLS).
TOTAL number of students = 18 + 21 = 39
Answer: E
Cheers,
Brent