Question

The chimps were either playful or sleepy. If the ratio of the number of playful to the number of sleepy was 7 to 5 and 2100 were observed, how many were sleepy?

Answer 1

2940

Explanation:

2100 x 7 = 14700

14700/5 = 2940

Answer 2

2940

Explanation:

Since

7 : 5 = X : 2100

Then we know

7/5 = X/2100

Multiplying both sides by 2100 cancels on the right

2100 × (7/5) = (X/2100) × 2100

2100 × (7/5) = X

Then solving for X

X = 2100 × (7/5)

X = 2940

Therefore

7 : 5 = 2940 : 2100