At a certain elementary school, 10 percent of the fifth-grade students are members of the school band. if 12 percent of the fifth-grade boys and 8 percent of the fifth-grade girls are members of the band, what percent of the fifth-grade students at the school are boys?

Let the 5-grade students be A in total.

Let b of these be boys, and g of these be girls, so b+g=A.

i) "At a certain elementary school, 10 percent of the fifth-grade students are members of the school band."

this means that the number of the members of the school band is :



ii)
"12 percent of the fifth-grade boys and 8 percent of the fifth-grade girls are members of the band"

this means that the number of the band members is:


equalizing these 2 ways of expressing the number of members of the band, we have:







so g=b

this means that 50% of the 5-grade students are boys.

50%