Question

A random number generator chooses 2 numbers between 1 and 5. This table demonstrates all possible outcomes. What is the probability that the computer will pick two 5s?


A. 0.08

B. 0.4

C. 0.2

D. 0.04

Answer 1

As the table shows, there are 25 possible outcomes. Actually, you could know this without listing all possible values, because you have 5 outcomes for the first number, and the same 5 outcomes for the second number, leading to a total of

$5\cdot 5=25$

possible couples.

So, the program will generate the couple (5,5) with a 1/25 chance, since (5,5) is one of 25 possible cases.

If you turn the number into decimal, you'll have

$\dfrac{1}{25}=0.04$