Question 739800
Average = (sum of the numbers)/(number of numbers)<P>
For the juniors 80 = sum/35 so sum = 80*35 = 2800.<P>
For the seniors 70 = sum/15 so sum = 70*15 = 1050.<P>
The sum of the juniors scores and the seniors scores is the sum of all the scores.  2800+1050 = 3850.<P>
Avg of all the students' scores is 3850/50 = 77
<P>Hope the solution helped.  Sometimes you need more than a solution.  Contact fcabanski@hotmail.com for online, private tutoring, or personalized problem solving (quick for groups of problems.)