Question

After 5 tests Dara's average score was 88 what score must she average on the next two tests to have a seven-test average of 90?

Answer 1

After 5 tests, her average was 88. To have a seven-test average of 90, the total must be:

$90 \times 7 = 630$

Her average after 5 tests was 88. Her total score on the 5 tests is:

$88 \times 5 = 440$

Subtract:

$630-440 = 190$

Find the average by dividing by 2:

$190 \div 2 = 95$

Her average must be 95