Question

Jackie scored 82 and 88 on her first two quizzes. Write and solve a compound inequality to find possible values for a third quiz score that would give her an average between 80 and 85, inclusive.

a. 80 <= 82 + 88 + n / 3 <= 85; 70 <= n <= 85

b. 70 <= 82 + 88 + n / 3 <= 85; 80 <= n <= 85

c. 80 <= 82 + 88 + n / 3 < 85; 70 < n < 85

d. 82 <= 80 + 85 + n / 3 <= 88; 70 <= n <= 85

Answer 1

the answer is a . first you can understand that b and d can not be the answers because the question says that hey score should be between 80 and 85 so between a and c the answer is a :)))
i hope this is helpful

Answer 2

Answer : option A

Jackie scored 82 and 88 on her first two quizzes

Let n be the score of third quiz

Average of 3 quiz =
`(82+88+n)/(3)`

average between 80 and 85, inclusive.

so average lies between 80 and 85

Question says 80 and 85 inclusive. so we use <= or >= symbol

So inequality becomes

`80<= (82+88+n)/(3) <= 85`

`80<= (170+n)/(3) <= 85` ( multiply all sides by 3)

`240<=170+n<= 255` (subtract all sides by 170)

`70<=+n<= 85`

so option A is correct