Question

A alone can complete the project in 10 days; B alone can complete it in 20 days while C alone can complete it in 30 days. They together earn Rs. 1,100 for the project. By how much do the total earnings of A and C exceed the earnings of B?

• A. Rs. 600
• B. Rs. 900
• C. Rs. 700
• D. Rs. 500

Answer 1

Answer:

D. Rs. 500

Solution: Given: A's time = 10 days, B's time = 20 days, C's time = 30 days, Total earning = Rs. 1,100 Concept Used: Work done is inversely proportional to time Calculation: ⇒ A's work/day : B's work/day : C's work/day = 1/10 : 1/20 : 1/30 = 6 : 3 : 2 ⇒ Earnings of A and C = (6 + 2)/11 × Rs. 1,100 = Rs. 800 ⇒ Earnings of B = 3/11 × Rs. 1,100 = Rs. 300 ⇒ Difference = Rs. 800 - Rs. 300 = Rs. 500 Therefore, the total earnings of A and C exceed the earnings of B by Rs. 500. ∴ Option 4 is the correct answer.