Civil Service Exam Reviewer · Ratio and Proportion · hard
A box has red and blue balls in the ratio 5 : 7. After 11 red balls are removed, the ratio becomes 29 : 56. How many blue balls are in the box?
- 40
- 56
- 96
- 67
Answer
B. 56
Solution
Red = 5k, blue = 7k. (5k − 11)/7k = 29/56 → k = 8. Blue = 7 × 8 = 56.
More Ratio and Proportion questions
- Ana and Tess share some money in the ratio 7 : 4. Ana receives ₱7,020 more than Tess. How much money was shared?
- 9 workers working 8 hours a day can finish a project in 10 days. How many days will 4 workers working 6 hours a day need to finish the…
- The ratio of the number of pupils to teachers in a school is 70 : 1. If there are 32 teachers, how many pupils must be added so that the…
- ₱10,670 is shared among A, B and C such that A : B = 1 : 2 and B : C = 4 : 5. How much does C receive?
- A gear with 70 teeth rotating at 300 rpm drives a gear with 35 teeth. How fast does the second gear rotate?
- Alloy X contains gold and copper in the ratio 1 : 4; alloy Y contains them in the ratio 1 : 5. If equal weights of X and Y are melted…
- The ratio of the number of pupils to teachers in a school is 90 : 1. If there are 16 teachers, how many pupils must be added so that the…
- 12 workers can complete a job in 24 days. After working for 18 days, 3 workers leave. How many more days will the remaining workers need…
- 15 carpenters can finish a job in 17 days. How many MORE carpenters are needed to finish it in 5 days?
- A box has red and blue balls in the ratio 5 : 6. After 12 red balls are removed, the ratio becomes 1 : 2. How many blue balls are in the…