Question

Cory's average score after 8 tests is 91%. If he gets a 78% on his 9𝑡ℎ test, what will his new average be?

Answer 1

Cory's total after 8 tests is 8 × 91 = 728. After a 78 on the 9th test the total is 806, so the new average is 806 ÷ 9 = 806/9 ≈ 89.555...%.

So his new average is 806/9% (about 89.6%).