Question

the ratio of boys to girls in mr. johnson’s after - school club is the same as the ratio of boys to girls in ms. greene’s after - school club. there are 4 boys and 12 girls in mr. johnson’s club. there are 6 boys in ms. greene’s club. how many girls are in ms. greene’s club?
a. 2
b. 12
c. 14
d. 18

Explanation:

Step1: Find Johnson's boy-girl ratio

Ratio = $\frac{\text{Boys}}{\text{Girls}} = \frac{4}{12} = \frac{1}{3}$

Step2: Set up Greene's ratio equation

Let $g$ = number of girls in Greene's club.
$\frac{6}{g} = \frac{1}{3}$

Step3: Solve for $g$

Cross-multiply: $g = 6 \times 3 = 18$

Answer:

D. 18