Sixteen minutes ago, 80% of the students in a hall were boys. 42 more students entered the hall. As a result, the number of boys increased by 40% and the number of girls increased by 80%. How many students are in the hall now?
| |
Boys |
Girls |
Total |
| Before |
5 u |
1 u |
6 u |
| Change |
+ 2 u |
+ 0.8 u |
+ 2.8 u |
| After |
7 u |
1.8 u |
8.8 u |
80% =
80100 =
45Number of more boys who entered the hall
= 40% x 5 u
=
40100 x 5 u
= 2 u
Number of more girls who entered the hall
= 80% x 1 u
=
80100 x 1 u
= 0.8 u
Total number of more students who entered the hall
= 2 u + 0.8 u
= 2.8 u
2.8 u = 42
1 u = 42 ÷ 2.8 = 15
Number of students in the hall now
= 7 u + 1.8 u
= 8.8 u
= 8.8 x 15
= 132
Answer(s): 132
