A tank can be filled in 20 minutes and emptied in 24 minutes using two lines, and a waste pipe can empty 3 gallons per minute. Working together, the three pipes can fill the tank in 15 minutes. The tank has the following capacity:
A. 60gallons
B. 100gallons
C. 120gallons
D. 180gallons
Answer:C
A tank can be filled in 20 minutes and emptied in 24 minutes using two lines, and a waste pipe can empty 3 gallons per minute. Working together, the three pipes can fill the tank in 15 minutes. The tank has the following capacity:
A. 60gallons B. 100gallons C. 120gallons D. 180gallons
Explanation: 1/15 -1/20+1/24 = 1/15 - 11 /120,[The -ve symbol denotes emptying] = - 1/40,3 gallons = 1/40 portion volume.(3 × 40) gallons = 120 gallons total volume.