At the sports meet, there were 81 less boys than girls. After
13 of the boys and
49 of the girls had left the hall, there was an equal number of boys and girls that remained behind. Find the number of boys who were present at the sports meet at first.
|
Boys |
Girls |
Less |
Before |
3x5 = 15 u |
9x2 = 18 u |
3 u |
Change |
- 1x5 = - 5 u |
- 4x2 = - 8 u |
|
After |
2x5 = 10 u |
5x2 = 10 u |
|
Fraction of boys that remained
= 1 -
13 =
23 Fraction of girls that remained
= 1 -
49 =
59 The number of boys and girls in the end is the same. Make the number of boys and girls in the end the same. LCM of 2 and 5 is 10.
2x53x5 Boys =
5x29x2 Girls
1015 Boys =
1018 Girls
Total boys at first = 15 u
Total girls at first = 18 u
Number of less boys than girls at first
= 18 u - 15 u
= 3 u
3 u = 81
1 u = 81 ÷ 3 = 27
Number of boys at first
= 15 u
= 15 x 27
= 405
Answer(s): 405