Management Aptitude Test Sep 2013 Paper

(a) Part of tank filled by pipe A in 1 h = 1 /30
Part of tank filled by pipe B in 1 h = 1/45
Then, part of tank filled in 2 h when one pipe is opened at a time
=

1

30

+

1

45

=

3+2

90

=

5

90

=

1

18

Now, let the tank takes x h to get filled.
Then,

1

18

×x = 1
x = 18 h
Also,

1

18

part is filled in 2 h
∴Tank is filled in 2x h = 2 × 18 = 36 h