Answer to Question #244919 in Statistics and Probability for Chrissy

Question

1.      A two-digit number between 10 and 99 inclusive is written down at random. What is the probability that it:

 

a)      Is divisible by 5?

 

 

b)     Is divisible by 9?

 

 

c)      Is greater than 40?

 

 

d)     Is a perfect cube?

Answer 1

a)

There are 18 numbers divisible by 5.

$P=18/90=1/5$

b)

There are 10 numbers divisible by 9.

$P=10/90=1/9$

c)

There are 59 numbers greater than 40.

$P=59/90$

d)

There are 2 perfect cubes.

$P=2/90=1/45$