In a school, 0.75 of the girls and 0.1 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 448 pupils take part in curricular activities, how many less pupils do not take part in curricular activities than those who take part in curricular activities?

Girls		Boys
Take part	Do not take part	Take part	Do not take part
3x9	1x9	1	9
	1x9		1x9
27 u	9 u	1 u	9 u

0.75 = ³₄
Girls that take part : Girls that do not take part = 3 : 1

0.1 = ¹₁₀
Boys that take part : Boys that do not take part = 1 : 9

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 9 is 9.

Number of pupils who take part in curricular activities
= 27 u + 1 u
= 28 u

28 u = 448

1 u = 448 ÷ 28 = 16

Number of pupils who do not take part in curricular activities
= 9 u + 9 u
= 18 u

Number of less pupils who do not take part in curricular activities than those who take part in curricular activities
= 28 u - 18 u 
= 10 u
= 10 x 16
= 160

Answer(s): 160