Gino’s mom has told him that he needs to take a bucket of water over to their neighbour since she is experiencing problems with her water supply. He doesn’t want to waste much time since he has a soccer game to play later in the afternoon. From past experience he knows if he uses the small hose it takes 45 minutes to fill the bucket with water. He also knows that the larger hose can do the same in 30 minutes. If he uses both hoses, how long will it take him to fill the bucket?
Answer
The small hose can fill 1/45 of the bucket every minute. The larger hose can fill 1/30 of the bucket every minute. To add the two speeds, we need to find a common denominator.
1/45 = 2/90 and 1/30 = 3/90
Adding the two speeds:
2/90 + 3/90 = 5/90 = 1/18
Since both hoses together can fill 1/18 of the bucket every minute, it will take 18 minutes. By doing this Gino will save at a minimum 12 minutes. This will get him to his soccer game just in time.
