In a school, 0.75 of the girls and 0.3 of the boys take part in quizzes. There is an equal number of boys and girls who do not take part in quizzes. If 120 pupils take part in quizzes, how many less pupils do not take part in quizzes than those who take part in quizzes?
Girls |
Boys |
Take part |
Do not take part |
Take part |
Do not take part |
3x7 |
1x7 |
3 |
7 |
|
1x7 |
|
1x7 |
21 u |
7 u |
3 u |
7 u |
0.75 =
34 Girls that take part : Girls that do not take part = 3 : 1
0.3 =
310 Boys that take part : Boys that do not take part = 3 : 7
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 7 is 7.
Number of pupils who take part in quizzes
= 21 u + 3 u
= 24 u
24 u = 120
1 u = 120 ÷ 24 = 5
Number of pupils who do not take part in quizzes
= 7 u + 7 u
= 14 u
Number of less pupils who do not take part in quizzes than those who take part in quizzes
= 24 u - 14 u
= 10 u
= 10 x 5
= 50
Answer(s): 50