Civil Service Exam Reviewer · Ratio and Proportion · hard
The ratio of the number of pupils to teachers in a school is 90 : 1. If there are 30 teachers, how many pupils must be added so that the ratio becomes 100 : 1?
- 3000
- 2700
- 10
- 300
Answer
D. 300
Solution
Current pupils = 90 × 30 = 2700. Needed = 100 × 30 = 3000. Add 300.
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