Question

A local business is holding a contest. They have a bag with 10 tiles in it, with each tile numbered from 11 through 20. They tell you to pick a card at random from the bag. What is the probability of winning if you need to pull a card divisible by 2?What is the odds of winning if you win when the number drawn is a Prime number (11, 13, 17, 19)Are your chances to win better if they say you win if the number is “Prime or divisible by 2” or “Prime and divisible by 2”? Explain your answer.

Answer 1

Part 1. The numbers divisible by 2 of the cards from 11 to 20 are:

12, 14, 16, 18, 20

Then, total card divisible by 2 = 5, so the probability is:

`P=(5)/(10)=(1)/(2)=0.5`

Answer: 0.5

Part 2. Prime numbers:

11, 13, 17, 19

Total card prime number = 4, then the probability is:

`P=(4)/(10)=(2)/(5)=0.4`

Answer: 0.4

Part 3.

We know that Prime numbers are all numbers that are divisible only by themselves and by 1, therefore prime numbers from 11 to 20 cannot be divisible by 2.

Answer: The odds of winning are better if the number is prime or divisible by 2.