Question

Find the probability of getting an even number from 20-30. *

5/9

6/9

4/9

7/9

​

Answer 1

Answer:

The probability of an event happening is desired outcome/sample space.

For our sample space, it’s just the number of numbers: 20.

The outcome you want has some overlap: 6. 12. 18. So, we’ll subtract these as they fit both criteria.

Even numbers: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 (10 numbers)

Multiples of 3: 3, 6, 9, 12, 15, 18 (6 numbers)

Pr(A or B) = Pr(A) + Pr(B) - Pr(overlap, also known as A intersect B)

Pr(even or mult. of 3) = 10/20 + 6/20 - 3/20 (the overlap)

= 13/20.

So, there is a 65% of you picking an even number or a multiple of three.

Answer 2

the probability is 4/9