Pipe A fills a tank of capacity 950 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? Select the correct option:  A) 57 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   950= 50*n =&gt; n = 19   here n = number of cycles.   total time = 19*3= 
<gadget id="calculator">19*3</gadget>
<output>57</output>
57 as in one cycle there are 3 minutes.   thus 57 minutes   57 minutesNSWER:57 minutes
<result>A</result>
Pipe A fills a tank of capacity 950 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?