Finding the average?

Question

A total of 50 juniors and seniors were given a mathematics test. The 35 juniors

attained an average score of 80 while the 15 seniors attained an average of 70. What

was the average score for all 50 students who took the test?

Answer 1

35 x 80 = 2800

and

15 x 70 = 1050

you just add 2800 + 1050

which equals 3850

and divide 3850 by 50

and you get 77.

the average score for all 50 students is 77.