VITEEE 2011 Paper

Let A and B be two events such that
A= getting number 2 at least once
B = getting 7 as the sum of the numbers on two dice
Here,
A= {(2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (1,2), (3,2), (4,2), (5,2), (6,2)} and
B = {(2,5), (5,2), (6,1), (1,6), (3,4), (4,3)}
∴ P (A) =

11

36

, P (B) =

6

36

P (A ∩ B) =

2

36

∴ Required probability
P (A/B) =

P(A∩B)

P(B)

=

2∕36

6∕36

=

2

6

=

1

3