Question

To get an A in a course, you must have an average of at least 90% on four tests worth 100 points each. Your scores on the first three tests were 89 , 

92 , and  81 . What must you score on the fourth test to get an A in the course? 

Answer 1

`4*100=400 -value \ of \ the \ four \ test \\ \\ 90 \% \ of \ 400= (90)/(100)*400=90*4=360 \ points \ is \ the \ minimal \\ \\ 89+92+81=262 -\ for \ the \ 3 \ test \\ \\ 360-262=98 \ points \ you \ have \ to \ take \ at \ the \ 4th \ exam`