Question

Two taps A and B can fill tank in 10 hours and 15 hours, respectively. If both the taps are opened together the tank will be full in:

• A. 8 hours
• B. 6 hours
• C. 5 hours
• D. None of these

Answer 1

The correct option is B 6 hours

Here, x = 10 and y = 15.
$\therefore$ The tank will be full in

$=\left(\frac{xy}{x+y}\right)hours$

$=\left(\frac{10\times 15}{10+15}\right)hoursor6hours.$