Question

Marina average 72 on her first three History exams the first score was 82. The second score was 4 less than the third what did she score on the second and third exams

Answer 1

First we will assign the variables

second exam: x

third exam: y

Because the second score is 4 less than the third

x=y-4

with this information, we can rewrite

second exam: y-4

third exam: y

Now, we have this equation of average

(82+y+y-4)/3=72

(2y+78)/3=72

then we can clear y

2y+78=216

2y=216-78

2y=138

y=138/2

y=69

69 on the third exam

65 on the second exam