Question

A tap can fill a tank in 16 hhours whereas another tap can
empty the tank it in 8 hours. If in a three fourth filled tank
both the taps are opened, then how long will it take to
empty the tank in this scenario?
A. 6 hours
B. 8 hours
C. 10 hours
D. 12 hours

Answer 1

Correct Answer - (d)
Let the capacity of the tank be C
Speed of inlet tap `= C//16`
Speed of outlet tap `= C//8`
Difference in speed ` =C/8 - C/16 = C/16 ` hours
Time to empty `3//4^(th)` of the tank ` = (3c//4)// C//16`
`=3C//4 xx 16//C=12` hours