At the concert, there were 72 less girls than boys. After
12 of the girls and
58 of the boys had left the hall, there was an equal number of girls and boys that remained behind. Find the number of girls who were present at the concert at first.
|
Girls |
Boys |
Less |
Before |
2x3 = 6 u |
8x1 = 8 u |
2 u |
Change |
- 1x3 = - 3 u |
- 5x1 = - 5 u |
|
After |
1x3 = 3 u |
3x1 = 3 u |
|
Fraction of girls that remained
= 1 -
12 =
12 Fraction of boys that remained
= 1 -
58 =
38 The number of girls and boys in the end is the same. Make the number of girls and boys in the end the same. LCM of 1 and 3 is 3.
1x32x3 Girls =
3x18x1 Boys
36 Girls =
38 Boys
Total girls at first = 6 u
Total boys at first = 8 u
Number of less girls than boys at first
= 8 u - 6 u
= 2 u
2 u = 72
1 u = 72 ÷ 2 = 36
Number of girls at first
= 6 u
= 6 x 36
= 216
Answer(s): 216