Question

Large rubber cushion can be filled with air pump in 10 minutes, another pump can fill the same cushion in 12 minutes. If both the pumps operate together, how long will it take to fill the cushion?

Answer 1

Answer:

Their work capacity is 1/10 and 1/12 , so combined work capacity

$\frac{1}{10} + \frac{1}{12} = \frac{10 + 12}{10 \times 12} = \frac{11}{60}$

So work done = 1/work capacity

= 60/11 = 5.45 minutes

Answer 2

X 1/10

Y 1/12

X+Y 6+5/60

60/11 MINS

=

5 5/11 MINS