In a school, 0.8 of the girls and 0.7 of the boys take part in curricular activities. There is an equal number of boys and girls who do not take part in curricular activities. If 90 students do not take part in curricular activities, how many more students take part in curricular activities than those who do not take part in curricular activities?

Girls		Boys
Take part	Do not take part	Take part	Do not take part
4x3	1x3	7	3
	1x3		1x3
12 u	3 u	7 u	3 u

0.8 = ⁴₅
Girls that take part : Girls that do not take part = 4 : 1

0.7 = ⁷₁₀
Boys that take part : Boys that do not take part = 7 : 3

The number of boys who do not take part is repeated.  Make the number of boys who do not take part the same.  LCM of 1 and 3 is 3.

Number of students who do not take part in curricular activities
= 3 u + 3 u
= 6 u

6 u = 90

1 u = 90 ÷ 6 = 15

Number of students who take part in curricular activities
= 12 u + 7 u
= 19 u

Number of more students who take part in curricular activities than those who do not take part in curricular activities
= 19 u - 6 u
= 13 u
= 13 x 15
= 195

Answer(s): 195