The ratio of boys to girls in a school is 1:4
The numbers of girls who wear glasses and the girls who don't are in the ratio 1:2
Calculate the number of girls who don't wear glasses, if there are 300 students altogether in this school
300 students in the school.
1/[1+4] x 300 =60 boys in the school
300 - 60 =240 girls in the school
1/[1+2] x 240 =80 girls who wear glasses
240 - 80 = 160 girls who don't wear glasses.