IBPS PO Prelims 23 Aug 2025 Shift 1 Solved Paper

Concept:Equate total work from both given conditions to find the efficiency ratio of a man and a woman.Explanation:Let efficiency of one man be $M$ and one woman be $W$.Total work is constant, so from the first condition:$$(15M + 10W) \times 30 = 450M + 300W$$From the second condition:$$(10M + 20W) \times 20 = 200M + 400W$$Equating the two expressions for total work:$$450M + 300W = 200M + 400W$$$$250M = 100W$$$$\frac{M}{W} = \frac{100}{250} = \frac{2}{5}$$So efficiency ratio of man to woman is $2 : 5$.Let $M = 2$ and $W = 5$ units of work per day.Total work $= 200(2) + 400(5) = 400 + 2000 = 2400$ units.One-third of total work:$$\frac{2400}{3} = 800 \text{ units}$$Efficiency of 6 men and 4 women:$$6(2) + 4(5) = 12 + 20 = 32 \text{ units/day}$$Required time:$$\frac{800}{32} = 25 \text{ days}$$Answer:6 men and 4 women will complete one-third of the work in $25$ days.Correct option: C. 25 days.