math,(fraction)
posted by Da S .
there were 25pupils in a class. they had 135 books altogether. twofifth of the pupils were girls.they had the same number of books each. the remaining pupils were boys.each boy had onethird as many as each girl.how many books did each girl have?

girls = 2/5 * 25 = 10
boys = 2510 = 15
If each girl had g books, each boy had g/3 book
total books: 10g + 15g/3 = 135
15g = 135
g = 9
so each girl had 9 books, each boy had 3.
10*9 + 15*3 = 90 + 45 = 135 books in all 
Girls= 2/5*25= 10
Boys = 3/5*25= 15
All books= 135 books
135÷3= 45÷15= 3*3
= 9 books