A teacher knows that 80% of her students will score no more than 5 points above or below the class average, 85%, on the test. Which inequality represents the test scores of 80% of her students?

a. 75<A<85
b. 85<=A<=90
c. 80<A<90
d. 80<=A<=90

Can you PLEASE elaborate ?

I think you are saying option c.

But real answer is d. Not sure why.

Question 1 options:

The scores on a math test for five students were posted on the bulletin board. The students' names are Tom, Penny, Fred, John and Jake. Tom and Jake scored the same number of points. Penny did not get the highest score. John's score was 5 points lower than Fred's. The scores were 80, 57, 90, 57, and 85. Which student received what scores?

top will get 90

bottom will get 80
so what do you think?

Because It could be EXACTLY 80 or EXACTLY 90

you can not just say less than 90 because you must include 90

therefore
less than OR EQUAL TO 90

Sorry but how do you know to include 80 and 90. Just cannot understand that part. Thanks much.