UPSC NDA I 2016 Mathematics Solved Paper

Since two dice are thrown so number of outcomes are 36.
No. of ways when sum on two faces less than 4=3
[(1,1),(1,2),(2,1)]
Hence prob of getting sum on two faces less than 4
=

3

36

=

1

12

Thus required prob. that sum on the two faces is greater than or equal to 4=1−

1

12

=

11

12