An inlet pipe on a swimming pool can be used to fill the pool in 29 hours. The drain pipe can be used to empty the pool in 30 hours. If the pool is 15 filled and then the inlet pipe and drain pipe are opened, how long from that time will it take to fill the pool?

Maybe the answer is 20mm. all i really did was just multiply, which is obvious.

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )