Q.

If an unbiased die, marked with −2, −1, 0, 1, 2, 3 on its faces, is thrown five times, then the probability that the product of the outcomes is positive, is          [2023]

1 4402592  
2 8812592  
3 27288  
4 5212592  

Ans.

(4)

The markings on an unbiased die are −2, −1, 0, 1, 2, 3.

P(positive number)=36=12

P(negative number)=26=13

Let A= Product is positive.

A=(5 positive numbers) or (1 positive, 4 negative) or (3 positive, 2 negative)

P(A)=C55(12)5+C15(13)4(12)1+C35(12)3×(13)2

=132+5162+1072=5212592