Two neighbors, Wilma and Betty, each have a swimming pool. Each pool holds 8,380 gallons of water. If Wilma's garden hose fills at a rate of 640 gallons per hour, while Betty's garden hose fills at a rate of 780 gallons per hour, how much longer does it take Wilma to fill her pool than Betty? (Enter time in minutes rounded to the nearest minute. For example, if the answer is 1 hour 20 minutes, you must enter "80" for 80 minutes.)

141 min

Step-by-step explanation:

Given, each pool holds 8,380 gal

Wilma's fill rate,

= 640 gal / hour = 640/60 gal/min = 10.667 gal / min

i. e 10.667 gal takes 1 minute

1 gal takes Wilma 1 : 10.667 min

8,380 gal takes Wilma (1:10.66) x 8,380 = 785.62 minutes

Betty's fill rate,

= 780 gal / hour = 780/60 gal/min = 13 gal / min

i. e 113 gal takes 1 minute

1 gal takes Wilma 1 : 13min

8,380 gal takes Wilma (1:13) x 8,380 = 664.615 minutes

Difference in time to fill 8,380 gal = 785.62 - 664.615 = 141 min (nearest min)