An Olympiad math problem, hurry up, hurry up, hurry up

1) Turn a few and a few fractions into a false fraction, it becomes: 3 2*4 3*5 4*6 5*...111 110=111 2 (2) In the first parentheses, +1 and then -1, that is, it becomes (1+1 2+1 3+1 4+..

1 2004-1) becomes [(1+1 2+1 3+1 4+..1/2004）-1】*（1+1/2+1/3+..1/2003）-（1+1/2+1/3+..

1/2004）*（1/2+1/3+1/4+..1 2003) The first two products are distributively become: (1+1 2+1 3+1 4+..)

1 2003) = 1 2004 Question 2, easy method: Let 1 plus 1/2 add to 1/1 of 2003 as x. Let one-half be added to 1/2003 as y.

Then the original equation = x(y+1 2004)-y(x+1 2004) last open = 1 2004 (x-y) final result = 1 2004

If the height of the water is h, the water volume of the water tank is 40 30 h = 1200h (cubic centimeters).

The volume of water in tank B is 30 20 h = 600h (cubic centimeters), and the volume of raw water is: 30 20 24 = 14400 (cubic centimeters), then: 14400 = 1200h + 600h

Solution: h=8cm

It can be seen from the title.

After pouring water, the ratio of the volume of water tank A and B is.

Therefore, the volume of water in tank A is (30*20*24) 3*2=9600, and the depth is: 9600 (40*30)=8cm

You see that the total volume of water in B is 30*20*24=14400, and then the total volume of the two of them is 14400, and let their height: h

Then h(40*30+30*20)=14400h=8, the answer is revealed..

Good luck!

1.The hound runs at least 60 meters to catch up.

2.According to the principle of multiplication, there are two steps:

The first step is to treat the five couples as five wholes, and there are 5 4 3 2 1 120 different arrangements for arrangement, but because they are enclosed in a circle that connects end to end, there will be 5 5 repetitions, so the actual arrangement is only 120 5 24 types.

In the second step, each couple can swap positions with each other, that is to say, each couple has 2 kinds of arrangement, a total of 2 2 2 2 2 32 kinds.

In two steps, there are 24,32,768 species.

3. 34+80+48-16-6-11=162-33=1294.Let the first speed be x and the second speed be y

1120-4x＝4y

56x-1120＝56y

Solution: x 150 m min, y 130 m min So, A 1 min walk 150 m. B walks 130 meters in 1 minute.