Question 1025076
he scored a total of 80 + 74 + 81 + 75 = 310 on the first 4 test.


to get an overall average of 80 on 5 tests, he has to score a total of 5 * 80 = 400 on all 5 tests.


400 - 410 = 90.


he has to score at least a 90 on the last test.


80 + 74 + 81 + 75 + 90 = 400


400 / 5 = average of 80.