Discuss Forum
1. Two different schools, A and B, have the same number of students. The ratio of the boys in school A and the boys in school B is 2:1 and the ratio of the girls in school A and the girls in school B is 4:5. What is the ratio of the boys in school A to the girls in school A?
- A. 1:2
- B. 1:2
- C. 1:2
- D. 1:2
Answer: Option A
Explanation:
school A has a boys and b girls, and school B has c boys and d girls, then
a/c = 2/1
b/d = 4/5
a+b = c+d
we want to find a/b
a = 2c
5b = 4d
a-c = d-b
a-(a/2) = (5b/4)-b
a/2 = b/4
a/b = 2/4 = 1/2
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