Problem: speed of a boat in standing water is 10 kmph and speed of the stream is 2.5 kmph . a man can rows to a place at a distance of 105 km and comes back to the starting point . the total time taken by him is ?
Rationale: "speed upstream = 7.5 kmph speed downstream = 12.5 kmph total time taken = 105 / 7.5 + 105 / 12.5 = 22.4 hours answer is b"
annotated_formula: add(multiply(add(add(10, 2.5), subtract(10, 2.5)), 105), multiply(subtract(add(divide(105, add(10, 2.5)), divide(105, subtract(10, 2.5))), add(add(10, 2.5), subtract(10, 2.5))), const_60))