A spinner is divided into 10 equal parts and numbered from 1 through 10. What is the probability of spinning a number less than 8 on the first spin and greater than 5 on the second spin?

Answer 1

Numbers less than 8 are 1, 2, 3 , 4, 5, 6, 7

a total of 7 numbers

Each number has a probability of 1 / 10

So the probability of spinning number less than 8 is

7 ∙ 1 / 10 = 7 / 10 = 70 %

Numbers less greater then 5 are 6, 7 , 8 , 9 , 10

a total of 5 numbers

Each number has a probability of 1 / 10

So the probability of spinning number greater then 5 is

5 ∙ 1 / 10 = 5 / 10 = 50%

If the spinner is spun twice the probability that first spinning the number is less than 8 and then spinning the number greater than 5 is the product of these probabilities.

7 / 10 ∙ 5 / 10 = 35 / 100 = 35%