Manipal Entrance Test 2016 Math Paper

Every time the selected coupon must be from 1 to 9. The probability of such a selection at any time is

9

15

=

3

5

and this can happen 7 times, i.e. (

9

15

)7.
Put of these (

9

15

)7,(

8

15

)7 cases do not contain the number 9.
Thus, the required probability =(

9

15

)7−(

8

15

)7