IBPS SO Prelims Exam Model Paper 2

GIVEN:
Prize has to be given to two teachers from six teachers present on the stage in which one teacher is sports teacher
FORMULA:
Probability of sports teacher not receiving the prize = 1 – (probability of sports teacher receiving the prize)
CALCULATION:
Total number of ways prize can be given to any two teachers from 6 teachers = 6C2 =

(6×5)

2

= 15
Probability of sports teacher receiving the prize:
Two persons receiving the prize one (sports teacher) is fixed. The second person can be selected from remaining 5 teachers in 5 ways.
Thus, probability =

5

15

=

1

3

Probability of sports teacher not receiving the prize = 1 – (probability of sports teacher receiving the prize)
= 1 – (

1

3

) =

2

3

∴ Sports teacher not getting the prize
Alternate Method:
Total number of ways prize can be given to any two teachers from 6 teachers = 6C2 =

(6×5)

2

= 15
Total number of ways sports teacher not getting the prize = 5C2 = 10
∴ Required probability =

10

15

=

2

3