75x+( 100-x)* 83 = 100 * 8 1
8x=8300-8 100
X=25 people
There are 25 boys and 75 girls.
2. There are x adults and 100-x children.
2x+ 100-x= 1 10
x= 10
Adults 10, 90 children.
3, 85*5-83*4=93 points
She got at least 93 points in the fifth exam.
4. 142 * 6- 14 1 * 5 = 147cm。
The height of the sixth person is 147 cm.