There are 3 stools in the room and 4 chairs in 40. The room is just 40 children sitting on it. Legs, chairs, legs, children, the number of legs is 225
First of all, remove the total number of legs of 40 children, 225 minus 80, and the remaining 145, that is, a total of 40 legs of 3 legs, plus 4 legs of the leg chair is 145, can be calculated 3 legs stool is 15, four legs chair is 25.
If the stool, chair, kids, kids were standing, two legs up, and sat on the left leg, a total of 225-40X2=145, is the chairs and stools, chairs or stools are no matter, a total of 3 amputated leg, left 145-40X3=25, 3 legs of the stool are the board... So there are 25 chairs, 15 stools, typing very tired.
