Twenty minutes ago, 60% of the children in a hall were boys. 10 more children entered the hall. As a result, the number of boys increased by 20% and the number of girls increased by 75%. How many children are in the hall now?
|
Boys |
Girls |
Total |
Before |
5 u |
2 u |
7 u |
Change |
+ 1 u |
+ 1.5 u |
+ 2.5 u |
After |
6 u |
3.5 u |
9.5 u |
60% =
60100 =
35Number of more boys who entered the hall
= 20% x 5 u
=
20100 x 5 u
= 1 u
Number of more girls who entered the hall
= 75% x 2 u
=
75100 x 2 u
= 1.5 u
Total number of more children who entered the hall
= 1 u + 1.5 u
= 2.5 u
2.5 u = 10
1 u = 10 ÷ 2.5 = 4
Number of children in the hall now
= 6 u + 3.5 u
= 9.5 u
= 9.5 x 4
= 38
Answer(s): 38