Question 248912
average score on first 6 mathematics tests is 84.


total score on first 6 tests = 6 * 84 = 504


average score on first 7 mathematics tests is 85.


total score on first 7 tests = 7 * 85 = 595


score on your 7th test is 595 - 504 = 91


(504 + 91) / 7 = 85 average on 7 tests.