Question

a student has scores of 76,72, and 75 on three exams. what minimum score is needed on a fourth fourth exam to make an average 80 or better?

Answer 1

so let the marks be x 

so 80 ≤ (76 + 72 + 75 + x)/4 

⇒ 320 ≤ 225 + x

⇒ x ≥  95  ANSWER

Answer 2

let the score be X
then (76+72+75+X)/4=80
⇒ x+223=320
⇒x=97
student has to score 97 or more.