The scores of Tim’s first four math tests are 82%, 90%, 78%, and 100%. If Tim wants to have a test average of 90%, what must the average of Tim’s next two tests be?
(A) 90% (B) 92% (C) 95% (D) 97% (E) 100%

Question

The scores of Tim’s first four math tests are 82%, 90%, 78%, and 100%. If Tim wants to have a test average of 90%, what must the average of Tim’s next two tests be?
(A) 90% (B) 92% (C) 95% (D) 97% (E) 100%

anonymous · Answer

the average so far is
(82 + 90 + 77 + 100) / 4

anonymous · Answer

87.5 % (i did use 78% for this result, typo above)

anonymous · Answer

so we need (87.5% + next_average ) / 2 =90%