In the following question, two statements are numbered as A and B. On solving these statements, we get quantities A and B respectively. Solve both quantities and choose the correct option. Quantity A: Twelve persons can construct a 320 m long wall in 32 days working 8 hours a day. In how many days can 40 persons construct a 250 m long wall working 10 hours a day? Quantity B: A can finish the work in 15 days and B in 30 days. They both work together for 5 days and then B leaves. How many days will A take to complete the remaining work? Correct Answer Quantity A Quantity A: We know that, M1D1H1/W1 = M2D2 H2/W2 M = Number of persons D = Number of days H = Number of hours W = Work done Given: M1 = 12, D1 = 32, H1 = 8, W1 = 320 M2 = 40, H2 = 10, W2 = 250 (12 × 32 × 8)/320 = (40 × D2 × 10)/250 D2 = 6 days Quantity B: One day work of A = 1/15 One day work of B = 1/30 One day work of (A + B) = (1/15 + 1/30) = 1/10 Five days’ work of (A + B) = 5 × 1/10 = 1/2 According to question, After 5 days B left the work So, the remaining 1/2 work is done by A Since, 1 work is done by A in 15 days So, 1/2 work is done by A in 7.5 days ∴ Quantity A