A and B undertook a work for Rs. 4200. A alone can do that work in 21 days. B alone can do the same work in 28 days. They started and completed the work together. What will be the difference in the amounts (in Rs.) they will receive?
Show answer & explanation
Correct answer: A
Explanation
Total work value = ₹4200
A works alone = 21 days
B works alone = 28 days
LCM of 21 and 28 = 84
Total work = 84 units
A's efficiency (work per day) = 84/21 = 4 units
B's efficiency (work per day) = 84/28 = 3 units
Ratio of A's efficiency to B's efficiency = 4 : 3
A's share = 4200 × 4/7 = ₹2400
B's share = 4200 × 3/7 = ₹1800
Difference in amounts = 2400 − 1800 = ₹600