Two pipes A and B can fill a tank in 12 and 24 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?
Choose the correct option
A) 9 min
B) 8 min
C) 6 min
D) 4 min
E) 5 min
Explanation:   Required time =12×24 / 12+24   =12 x 24/36   =24/3= 
<gadget id="calculator">24/3</gadget>
<output>8</output>
8 minutes   Answer: Option 8 min
<result>B</result>
Two pipes A and B can fill a tank in 12 and 24 minutes respectively. If both the pipes are used together, then how long will it take to fill the tank?