CMA Foundation · Fundamentals of Business Mathematics and Statistics · Ratios, Variations and Proportions
The time taken to complete a job by a team varies inversely with the number of workers. If 12 workers complete a job in 15 days, how many days will 20 workers take to complete the same job?
20 workers will take 9 days. Because time varies inversely with workers, the product of workers and days stays constant at 180 (12 × 15), so dividing 180 by 20 workers gives 9 days.
- A25 days
- B9 daysCorrect
- C12 days
- D8 days
Explanation
Workers × days is constant: 12 × 15 = 180. So 20 × d = 180, giving d = 9 days. The option 25 days results from treating the relationship as direct (15 × 20/12).
Did you get it right without looking?
One question tells you little. A timed set on Ratios, Variations and Proportions shows your real accuracy, how long you take and where you lose marks.
More Ratios, Variations and Proportions questions
- A contractor's 20 men working 8 hours a day can build 120 metres of road in 15 days. How many days will 30 men working 6 hours a day need to…
- A sum of ₹7,200 is to be divided among Arun, Bala and Chitra so that Arun's share : Bala's share = 2 : 3 and Bala's share : Chitra's share =…
- The ratio 5:8 is to be made equal to a ratio in proportion with 35:k. Find k.
- The monthly electricity cost C of a factory varies jointly with the number of machines M and the hours H run per day. When 8 machines run 6 …
- A firm's monthly sales to purchases are in the ratio 7:5. If sales for a month are ₹4,90,000, what is the amount of purchases?
- The monthly incomes of Sunil and Tarun are in the ratio 5:4 and their expenditures are in the ratio 3:2. If Sunil saves ₹4,000 and Tarun sav…