from an island , it is possible to reach the mainland by either ferry p or ferry q . ferry p travels for 3 hours at 6 kilometers per hour , while ferry q takes a route that is three times longer . if ferry p is slower than ferry q by 3 kilometers per hour , how many hours longer is the journey of ferry q compared with the journey of ferry p ?
"the distance traveled by ferry p is 18 km . then the distance traveled by ferry q is 54 km . ferry q travels at a speed of 9 kph . the time of the journey for ferry q is 54 / 9 = 6 hours , which is 3 hours more than ferry p . the answer is c ."
subtract(divide(multiply(const_3, multiply(6, 3)), add(6, 3)), 3)