Interesting topic 2: two candles with the same length, the first one can be lit for 4 hours, and the second one can be lit for 3 hours at the same time.
After these two candles are lit, the length of the first one is twice as long as the second one in a few hours.
Interesting question 3: Add 168 to a certain number to get the square of a positive integer, and add 100 to get a positive integer.
Square. What's the number, please?
Interesting question 4: Someone walked for five hours, first along the flat road, then up the mountain, and finally back along the original road.
In situ. If he walks 4 kilometers per hour on the flat road and 3 kilometers per hour on the mountain, every time he goes down the mountain,
He walked six kilometers in an hour. How many kilometers did he walk in five hours?
Interesting question 5: Miss Zhao's age has the following characteristics: (1) Its cubic power is a four-digit number, while its fourth power.
It is a six-digit number; (2) The digits of these four digits and six digits are exactly the ten digits of 0-9.
Numbers. Q: How old is Miss Zhao this year?
Interesting topic 6: On the racetrack, there are three horses, A, B, C, A can run twice in one minute, and B can.
Run three laps, and C can run four laps. Now three horses are side by side at the starting line, ready to go to the same side.
Here we go. Excuse me: after a few minutes, can these three horses run side by side at the starting line again?
Interesting question 7: There are four numbers, and the sum of any three numbers is 84, 88 and 99 respectively.
1 10, try to find these four numbers.
Interesting question 8: In the same plane, 1 circle divides the plane into two parts, and two circles divide the plane into four parts at most.
Part, ... So how many parts does the 10 circle divide the plane into at most?
Interesting question 9: A person walks from point M, turns right 20 meters ahead 15 degrees, and then goes 20 meters ahead.
Turn right at 15 degrees, ................................................................................................................................................................., if possible, he
How many meters did Yi * * walk back to M?
Interesting topic 10: When two different coins are tangent and the other circle rolls back to the starting point around the other circle,
How many times has this circle rotated?