Management Aptitude Test Sep 2013 Paper

(a) For first cube, probability of getting red face =

5

6

and probability of getting blue late =

4

6

Now, let the number of faces which are coloured red in colour = x
∴ Number of blue faces = 6 - x
Similarly, for second cube,
Probability of getting red face =

x

6

and probability of getting blue face =

6−x

6

Then, by given condition,

5

6

×

x

6

+

1

6

×

6−x

6

=

1

2

5

36

x+

6−x

36

=

1

2

5x+6−x

36

=

1

2

4x + 6 = 18
4x = 18 - 6 = 12
x =

12

4

= 3
∴ Number of red faces on second cube = 3