Pipe A fills a tank of capacity 800 liters at the rate of 40 liters a minute. Another pipe B fills the same tank at the rate of 30 liters a minute. A pipe at the bottom of the tank drains the tank at the rate of 20 liters a minute. If pipe A is kept open for a minute and then closed and pipe B is open for a minute and then closed and then pipe C is open for a minute and then closed and the cycle is repeated, when will the tank be full?  Choose the correct choice from the following
A) 48 minutes	B) 14 minutes	C) 39 minutes	D) 40 minutes 20 seconds	E) None of these
In one cycle they fill 40+30-20= 
<gadget id="calculator">40+30-20</gadget>
<output>50</output>
50 liters   800= 50*n =&gt; n = 16   here n = number of cycles.   total time = 16*3= 
<gadget id="calculator">16*3</gadget>
<output>48</output>
48 as in one cycle there are 3 minutes.   thus 48 minutes   48 minutesNSWER:48 minutes
<result>A</result>
Pipe A fills a tank of capacity 800 liters at the rate of 40 liters a minute. Another pipe B fills the same tank at the rate of 30 liters a minute. A pipe at the bottom of the tank drains the tank at the rate of 20 liters a minute. If pipe A is kept open for a minute and then closed and pipe B is open for a minute and then closed and then pipe C is open for a minute and then closed and the cycle is repeated, when will the tank be full?