Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 5 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?  Choose the most appropriate option.
A) 60 gallons	B) 200 gallons	C) 120 gallons	D) 180 gallons	E) 130 gallons
Work done by the waste pipe in 1 minute = 1/15 - (1/20 + 1/24) = - 1/40   Volume of 1/40 part = 5 gallons\   Volume of whole = 5 * 40= 
<gadget id="calculator">5 * 40</gadget>
<output>200</output>
200 gallons.   ANSWER:200 gallons
<result>B</result>
Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 5 gallons per minute. All the three pipes working together can fill the tank in 15 minutes. The capacity of the tank is?