(y+ 1)×6=(y- 1)×9

y=5

(5+ 1) × 6 = 36 people

There are 36 students in this class.

2. "Two of them each wipe 4 pieces, the others each wipe 5 pieces" and let the rest be y.

2×4+5y+ 12=(2+y)×6

y=8

8+2 = 10 people

10×6=60 pieces

A: There are 65,438+00 people cleaning the glass, and there are 60 pieces of glass.

Let's assume that the PE teacher has Y yuan with him.

(y+42)÷ 10 =(y+ 1000- 13)÷3 1

(y+42)×3 1 =(y+ 1000- 13)× 10

y=408

A: The PE teacher used to have 408 yuan on him.

4. Let Xiao Ming arrive at school no earlier or later than y minutes.

(y+5)×50=(y-5)×(50+ 10)

y=55

(55+5) × 50 = 3000m

5. Let the number of boys be X and the number of girls be Y..

88(x+y)=92x+82y

88x+88y=92x+82y

4x=6y

x÷y=4÷6= 1.5

A: The number of boys is 0.5 times that of 65438+ girls.

At 6.8 o'clock, when Xiao Ming came out from home, the alarm clock at home showed the time of 1 1:20, indicating that Xiao Ming went out for 3 hours and 20 minutes, MINUS one and a half hours, which was equal to 1 hour and 50 minutes. That is 1 10 minutes-for Xiaoming's round trip *110 ÷ 2 = 55009:15 minus 55 points equals 8:20, which means Xiaoming actually left home at 8:20. So it is accurate for Xiao Ming to set the alarm clock to 1 1:40 when he comes home.