Eighteen minutes ago, 70% of the pupils in a school field were boys. 47 more pupils entered the school field. As a result, the number of boys increased by 20% and the number of girls increased by 90%. How many pupils are in the school field now?
|
Boys |
Girls |
Total |
Before |
10 u |
3 u |
13 u |
Change |
+ 2 u |
+ 2.7 u |
+ 4.7 u |
After |
12 u |
5.7 u |
17.7 u |
70% =
70100 =
710Number of more boys who entered the school field
= 20% x 10 u
=
20100 x 10 u
= 2 u
Number of more girls who entered the school field
= 90% x 3 u
=
90100 x 3 u
= 2.7 u
Total number of more pupils who entered the school field
= 2 u + 2.7 u
= 4.7 u
4.7 u = 47
1 u = 47 ÷ 4.7 = 10
Number of pupils in the school field now
= 12 u + 5.7 u
= 17.7 u
= 17.7 x 10
= 177
Answer(s): 177