Question

Mariah has a spinner that has 10 equal sections, each containing a different number from 1 to 10. Mariah determines about how many times the spinner will land on a number that is greater than 7 in 250 spins, and her work is shown below.
P(number greater than 7)= Numbers greater than 7/ Total number of sections times number of spins = 4/10 (250) = 100

What mistake did Mariah make, if any?

Answer 1

She wrote a 4 instead of a 3.

There are only 3 numbers that are greater than 7. They are 8, 9, and 10. Mariah must have include 7 in her list. That is how she got 4 instead of 3.

Answer 2

Answer and step-by-step explanation:

There are 3 numbers greater than 7 on this spinner:  8, 9 and 10.  Mariah wrote 4 instead of 3, which makes her probability higher.  

She should have:

3/10(250) = 750/10 = 75