Arithmetichard · Past Paper

The ratio of students in three classes is 2:3:5. If 20 students are increased in each class, ratio becomes 4:5:7. Total students initially:

A100
B120
C150
D200

✓ Correct Answer: A100

Difference in ratio units is 2 (4-2, 5-3, 7-5). 2 units = 20, so 1 unit = 10. Initial total = (2+3+5)*10 = 100.

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