how much of the job does each pump do in an hour?
1/12 + 1/16 = 1/x
together they take x hours.
The Timuga swimming pool, of Manila City has two pumps it uses to fill the pool. If one pump takes 12 hours to fill the pool and the other pump alone takes 16 hours to fill the pool, how long will it take both pumps working together to fill the pool?
3 answers
48
Here's what I got.
Amount of pool filled by both the pumps is
1/12 + 1/16 = 7/48
Use common ratios of (amount of pool)/(time):
(7/48)/1 = 1/x
Cross multiply:
x = 48/7 = 6.9 hours, or more precisely
6 hours, 51 minutes, and 26 seconds
Amount of pool filled by both the pumps is
1/12 + 1/16 = 7/48
Use common ratios of (amount of pool)/(time):
(7/48)/1 = 1/x
Cross multiply:
x = 48/7 = 6.9 hours, or more precisely
6 hours, 51 minutes, and 26 seconds