+0  
 
0
29
1
avatar

Two different numbers are selected simultaneously and at random from the set {1,2,3,4,5,6,7}. What is the probability that the positive difference between the two numbers is 3 or greater? Express your answer as a common fraction.

 Dec 16, 2020

Best Answer 

 #1
avatar
+1

There are: 7 nCr 2 = 21 differences as follows:

 

(1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 6)>>Total = 21

 

Simply count all the numbers from 3 and up and divide the total by 21, and that would be the probability.

 Dec 16, 2020
 #1
avatar
+1
Best Answer

There are: 7 nCr 2 = 21 differences as follows:

 

(1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 5, 5, 6)>>Total = 21

 

Simply count all the numbers from 3 and up and divide the total by 21, and that would be the probability.

Guest Dec 16, 2020

27 Online Users

avatar
avatar
avatar