Question

In a class of 35 students, 25 girls averaged 92% on the last test, while the 10 boys averaged 85% on the same test. What is the average for the entire class on this test?

Answer 1

$the\ weighted\ average\ is=25\cdot92\%+10\cdot85\%=35\cdot x\%\ /\cdot100\\ \\2300+850=35x\ \ \ \Rightarrow\ \ \ 35x=3150\ /:35\\ \\x=90\\ \\Ans.\ the\ average\ for\ the\ entire\ class\ is\ 90\%$