100 points Grade 4 Math Olympiad! Help!

+(1-3 15) (1 12+1 15) = 3 + 16 3 = 8 and 1/3

3. A is less than B: 15 9=135

The distance between the two places: 135 (1-2 5-2 5)=675

1 8-1 12=1 24 1 (1 24)=24 days1-1 15*3) (1 12+1 15)+3=eight and a third (days)2 5) 9=2 45 (1-2 5) 9=3 45 15 (3 45-2 45)=675 (km).

40% 9=2 45 (1-40&) 9=1 15 1 (1 15)=15 (hours).

1 8-1 24 = 1 12 1 (1 12) = 12 (hours).

1. Typing a manuscript, A and B will take 8 hours to complete it, B will take 12 hours to complete it alone, and how many hours will it take for A to complete it alone?

1 8-1 12 = 1 24 1 (1 24) = 24 days.

2. The printing house wants to print a book, the master himself will take 12 days to complete, the apprentice will take 15 days to complete, and the two will work together for a few days, and the rest will be arranged by the apprentice for 3 days to complete the task, how many days will the apprentice arrange in total?

1-1 15*3) (1 12 + 1 15) + 3 = eight and a third (days).

3. A and B two cars at the same time from the two places opposite each other, after 9 hours of meeting, when meeting A traveled the whole 2 5, A traveled 15km less per hour than B, how many kilometers are the two places apart?

2 5) 9=2 45 (1-2 5) 9=3 45 15 (3 45-2 45)=675 (km).

4. Two cars A and B drove out of AB at the same time, and met in 9 hours, and when they met, car A traveled 40% of the total length, and car B traveled in several hours.

40% 9=2 45 (1-40&) 9=1 15 1 (1 15)=15 (hours).

5. Typing a manuscript, A and B work together in 8 hours to complete, B alone Yao 12 hours to complete, and A solo to complete how many hours to complete?

1 8-1 24 = 1 12 1 (1 12) = 12 (hours).

If you buy a book x book, you can buy a diary 32-x book, there is.

Let's say it's all a diary.

Then the flipbook: (Ben).

Diary: 32-21 = 11 (books).

1. Let the total distance be x, the meeting time of B and C is x 90, the distance of A is 30 * x 90 = x 30, and the distance of C is 5 x 9

The distance between the two is x-x 3-5x 9=x 9So x 9 = 10 * (30 + 50) solves x = 7200

2. Let a total of x people, pear saplings are 3x+2, and apples' are 7x-6, and there is equation 2 (3x+2)=7x-6 to get x=10

Pear sapling 32 apple 64

3. Let the four numbers be a, b, c, d

a+b+c)/3+d=26

a+c+d)/3+b=32

a+b+d)/3+c=40

b+c+d)/3+a=46

The sum of the four formulas is 2 (a+b+c+d) = 144

The original 4 averages are (a+b+c+d) 4=18 is not easy to play, I hope you can understand!!

2/11 9/11 4/11

In fact, you can remove the denominator first, use the integer numerator to participate in the calculation, and add the denominator after the calculation.

I'll give you a look at the numerator, the first line 2, 9, 4

Second line 7, 5, 3

Third line 6, 1, 8

It's the same thing!

Or: 8 1 6