tom reads at an average rate of 30 pages per hour , while jan reads at an average rate of 40 pages per hour . if tom starts reading a novel at 4 : 30 , and jan begins reading an identical copy of the same book at 5 : 20 , at what time will they be reading the same page ?
"relative speed = jan - tom = 10 pages per hour = 1 / 6 page per minute time diff = 50 minutes by the time jan started tom already finished ( 30 / 60 ) * 50 = 25 pages time taken = 25 / ( 1 / 6 ) = 25 * 6 = 150 minutes = 7 : 50 answer : d"
divide(add(5, divide(multiply(add(subtract(5, 4), divide(subtract(20, 30), const_60)), 30), subtract(40, 30))), 20)