Two pipes P and Q can fill a tank in 5 hours and 10 hours respectively. If both pipes are opened simultaneously, how much time will be taken to fill the tank? Choose the correct choice from the following answers
A) 4 hours 20 min B) 5 hours 49 min C) 3 hours 20 min D) 3 hours 22 min E) 3 hours 42 min
Explanation:   Part filled by P in 1 hour = 1/5   Part filled by Q in 1 hour = 1/10   Part filled by (P + Q) in 1 hour = ( 1/5 + 1/10) = (3/10)   Time taken to fill the tank is (10/3) = 10/3*60= 
<gadget id="calculator">10/3*60</gadget>
<output>200</output>
200 mins= 3 hrs 20 mins   ANSWER 3 hours 20 min
<result>C</result>
Two pipes P and Q can fill a tank in 5 hours and 10 hours respectively. If both pipes are opened simultaneously, how much time will be taken to fill the tank?