Question

a man's marksmanship scores are 6 and 10 respectively in two trials. if he wishes to average 9 on three trials. what must his third score be??

Answer 1

11

Explanation:

average = sum / count

count = 3 (there are three trials)

average = 9

9 = sum / 3

sum = first score + second score + third score

= 6 + 10 + third score

9 = (6+10+third score)/3

multiply both sides by 3 to remove the denominator

27 = 6 + 10 + third score

= 16 + third score

subtract 16 from both sides to isolate the third score

11 = third score