Civil Service Exam Reviewer · Ratio and Proportion · hard
The ratio of the number of pupils to teachers in a school is 50 : 1. If there are 21 teachers, how many pupils must be added so that the ratio becomes 60 : 1?
- 1260
- 1050
- 10
- 210
Answer
D. 210
Solution
Current pupils = 50 × 21 = 1050. Needed = 60 × 21 = 1260. Add 210.
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