Question

Which button helps us add a new background

Answer 1

Answer:

ANSWER

Work efficiency of pump A in emptying pool =

4

1

per hour

Work efficiency of pump B in emptying pool =

6

1

per hour

∴ work done by A and B together =

4

1

+

6

1

=

24

10

per hour

Hence time taken to fill the tank 100% =

10

24

hours

∴ time taken to fill 50% =

5×100

12×50

= 1.2 hours

Since, 1hour=60minutes

∴1.2 hours= 1.2×60=72 minutes

72 minutes = (60+12) minutes = 1hour 12minutes

So, the answer is option A

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