Here let boys = b and girls = g

and total students = 100

i.e. b + g =100 --------- equ 1

10% of the students are member of school band = 10% of 100 = 10 students.

out of which 12% are boys and 8% are girls

i.e. 0.12b + 0.08g = 10 ----------equ 2

Now multiplying equation 1 by 0.12,

0.12b + 0.12g =12 ---------equ 3

equ 2 - equ 3

0.04g = 2

or g = 50

Hence b= 50 (from equation 1)

Therefore there are 50% fifth-grade students at the school are boys. option E
_________________

If you found this post useful, please let me know by pressing the Kudos Button


Rules for Posting https://greprepclub.com/forum/rules-for ... -1083.html

Hello!!!
I think that solving such problems is useful for students who study at school. They can try the mathematical activity that is here http://www.bbc.co.uk/skillswise/game/ma08addi-game-bargain-hunt-adding in order to understand whether he or she can solve a similar mathematical problem like there is on this thread!