- A₹280
- B₹120
- C₹130
- D₹150
Step-by-Step Solution
B in 40 min fills ; A must fill , i.e. run 10 min. Cost . (₹280 runs both for 40 min; ₹120 is B alone, which is too slow.)
Answer: C) ₹130
Pump A fills a tank in 30 minutes at a running cost of ₹ 5 per minute; pump B fills it in 60 minutes at ₹ 2 per minute. The empty tank must be full in exactly 40 minutes. If B runs the whole 40 minutes and A only as long as needed, what is the least cost?
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