Civil Service Exam Reviewer · Ratio and Proportion · hard
Two numbers are in the ratio 5 : 7. If 9 is added to each, the ratio becomes 4 : 5. What is the larger of the original numbers?
- 30
- 15
- 39
- 21
Answer
D. 21
Solution
Let the numbers be 5k and 7k. (5k + 9)/(7k + 9) = 4/5 → k = 3. Larger = 7 × 3 = 21.
More Ratio and Proportion questions
- The ratio of the number of pupils to teachers in a school is 30 : 1. If there are 16 teachers, how many pupils must be added so that the…
- 14 workers can complete a job in 30 days. After working for 25 days, 4 workers leave. How many more days will the remaining workers need…
- ₱26,750 is shared among A, B and C such that A : B = 4 : 3 and B : C = 1 : 6. How much does C receive?
- A box has red and blue balls in the ratio 2 : 7. After 10 red balls are removed, the ratio becomes 3 : 28. How many blue balls are in the…
- Two similar rectangles have corresponding sides in the ratio 5 : 6. What is the ratio of their areas?
- A gear with 56 teeth rotating at 140 rpm drives a gear with 32 teeth. How fast does the second gear rotate?
- Alloy X contains gold and copper in the ratio 4 : 5; alloy Y contains them in the ratio 5 : 1. If equal weights of X and Y are melted…
- The ratio of the number of pupils to teachers in a school is 30 : 1. If there are 24 teachers, how many pupils must be added so that the…
- ₱26,640 is shared among A, B and C such that A : B = 1 : 4 and B : C = 5 : 3. How much does C receive?
- Two similar boxes have corresponding sides in the ratio 1 : 5. What is the ratio of their volumes?