Question

In 1st block, 45% of the class are juniors and 50% of the class are seniors. The remaining 2 students are sophomores. How many students are in the class altogether?

Answer 1

x = the total number of students

45x/100 + 50x/100 + 2 = x

9x/20 + x/2 + 2 = x

we put under denominator 20

(9x+10x+40)/20 = 20x/20

19x+40=20x

19x-20x=-40

x= 40

there are 40 students

Explanation:

Answer 2

5% - 2 students
45% - 18 students
50% - 20 students

Altogether: 100%/40 students.