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There are three math problems that can't be solved.
1. Someone asked Zhang San and Li Si about Wang Wu's age.

Zhang San said: "I am 22 years old this year. Two years younger than Li Si. Than Wang Wuda 1 year. "

Li Si said, "I am not the youngest. Wang Wu and I are three years apart. Wang Wu is 25 years old. "

Wang Wu said, "I am older than Zhang Xiaosan. Zhang San is 23 years old. Li Si is three years older than Zhang San. "

The above three sentences are deliberately wrong, so Wang Wu's real age is 22.

Zhang San 23 Li Si 25 Wu Wang 22

2. If the height of a cuboid is reduced by a part, the remaining part becomes a cube with a side length of 5 cm, and the volume is reduced by 100 cubic centimeter, and the surface area of this cuboid is reduced by 80 square centimeters.

The reduced height is 100/(5*5)=4.

The surface area is reduced to 5*4*4 (surface area) =80.

3. Party A and Party B run towards each other around the circular runway at a uniform speed, starting at both ends of the circular diameter. If they start at the same time, A meets 60 meters for the first time and B meets 80 meters for the second time, then how long is the circular runway?

Let the circular runway be S.

Then meet for the first time, Party A and Party B run S/2, and Party A runs 60.

At the second meeting, Party A and Party B ran 3S/2 and Party A ran S/2+80.

Because it is moving at a constant speed, the ratio of the distance that A runs to the distance that A and B run together remains unchanged.

S/2: 60 = 3s/2: (S/2+80) gives S=200.