a boat covers a certain distance downstream in 1 hour , while it comes back in 11 ⁄ 2 hours . if the speed of the stream be 3 kmph , what is the speed of the boat in still water ?
"explanation : let the speed of the water in still water = x given that speed of the stream = 3 kmph speed downstream = ( x + 3 ) kmph speed upstream = ( x - 3 ) kmph he travels a certain distance downstream in 1 hour and come back in 11 ⁄ 2 hour . ie , distance travelled downstream in 1 hour = distance travelled upstream in 11 ⁄ 2 hour since distance = speed × time , we have ( x + 3 ) × 1 = ( x − 3 ) ( 3 / 2 ) = > 2 ( x + 3 ) = 3 ( x - 3 ) = > 2 x + 6 = 3 x - 9 = > x = 6 + 9 = 15 kmph . answer : option b"
divide(add(multiply(divide(const_3, const_2), const_3.0), 2), subtract(divide(const_3, const_2), 1))