In how many cities is the number of females who appeared in Exam I more than…

Concept

If a total is divided in the male-to-female ratio m:f, the female count is total × f/(m + f). Apply this formula separately to each city and then count only the values strictly greater than the threshold.

Application

1. City A: 7,800 × 7/(6 + 7) = 4,200 females; 4,200 is greater than 4,000.

2. City B: 10,000 × 4/(1 + 4) = 8,000 females; 8,000 is greater than 4,000.

3. City C: 80,000 × 3/(5 + 3) = 30,000 females; 30,000 is greater than 4,000.

4. City D: 90,000 × 7/(2 + 7) = 70,000 females; 70,000 is greater than 4,000.

5. City E: 6,000 × 3/(2 + 3) = 3,600 females; 3,600 is not greater than 4,000.

Cross-check

The qualifying cities are A, B, C, and D, while E remains below the threshold. Thus, the required number of cities is 4.