RBI Assistant Prelims 2015 Sitting 1 Paper

Time taken by C = x days
C is 40% less efficient than A.
Time taken by A = 0.6x days
(A + B)'s 1 day's work =

1

10

...(i)
(B + C)'s 1 day's work =

1

15

...(ii)
Equation (i) - (ii),
(A - C)'s 1 day's work

1

10

−

1

15

=

1

30

1

0.6x

−

1

x

=

1

30

⇒

2

x

=

1

10

⇒x=2×10=20‌days