Marianna average 84 on her first three history exams. The first score was 67 the second score was seven less than the third scor

Question

masha68 [24]

4 years ago

6

Marianna average 84 on her first three history exams. The first score was 67 the second score was seven less than the third scor

e. What did she score on the second and third exams?

Mathematics

1 answer:

wel · Answer 1 · 2021-11-28T18:22:31+03:00

wel4 years ago

7 0

Let S=score on the second exam, then
(67+S+(S+7))/3=84
cross multiply
2S+74=252
2S=178
S=89
So second exam: 89
third exam=89+7=96
Check: (67+89+96)/3=84 ok.