ssr300 wrote:

What is the probability of getting a number on the first throw greater than that on the second throw when a dice is thrown twice?

A. 1/6

B. 2/3

C. 5/12

D. 7/12

E. 5/6

Hi,

1) simple logic should tell us that answer should be near but LESS than 1/2..

As we are dealing with duplicate patterns.. 1 and 6..... 2 and 5...3 and 4...

C should be the guess..

Why it should be near half is in the method below.

2) there can be six numbers in first throw and six in second , so ways = 6*6*=36..

Now if 1 is in first throw, any number in 2nd throw except 1 itself will give you ans YES, so 5 throw..

But in 2, all except 1 and itself will bE so 6-2=4 ways..

Similarly 3,2,1 and 0 for number 4,3,2,and 1respectively in first throw..

Possible ways=5+4+3+2+1+0=15..

Prob =15/36=5/12..

C

exactly my approach...yet I used approximations.

E is too big.