Question

Out of 30 consecutive numbers , 2 are chosen at random .find the probability that their sum is odd

Answer 1

1/2 is probabbility

Answer 2

Case 1,

The chosen number are odd and even

Thus their sum will be odd

P( getting odd ) = 1

Case 2

The chosen number are both odd

Thus their sum will be even


P( getting odd ) = 0

Case 3

The chosen numbers are both even

Thus their sum will be also even

P( getting odd ) = 0

Summing the three cases

P( getting odd ) = 1/3

Thus the answer is 1/3

Hope this helps