In a group of children, the average (arithmetic mean) weight of the boys is 60 pounds, and the average weight of the girls is 48 pounds. If the average weight of all of the children in the group is 50 pounds, what is the ratio of the number of boys to the number of girls?
A.1/12
B. 1/6
C. 1/5
D. 1/4
E. 1/3

Respuesta :

Answer:

C

Step-by-step explanation:

Let the number of boys be b and the number of girls be g. We will make equations from the statements in the question.

Since the average weight of the boys is 60, the total weight of the boys is 60b , in likewise manner, the average weight of the girls is 48g

Using the arithmetic mean of both:

60b + 48g/(b + g) = 50

60b + 48g = 50b + 50g

60b -50b = 50g - 48g

10b = 2g

b/g = 2/10

b/g = 1/5