UPSC NDA Math Model Paper 6

Probability of Dhoni making a century =

4

5

.
Probability of Dhoni not making a century =1−

4

5

=

1

5

.
Probability of Dhoni making no century in three matches:
P(not century) AND P(not century) AND P(not century)
P(not century) × P(not century) × P(not century)
=

1

5

×

1

5

×

1

5

=

1

125

∴ Probability of matches =1−

1

125

=

124

125