Two students-mathematicians, having birthdays on the same day, wished each other many happy returns on this day. One of them said:
- You’ll have such birthday only in 11 years.
The other answered him:
- Okay, but you’ll have such birthday only in 96 years.
Both of them were satisfied with each other. How old were they on this day ?
S o l u t i o n. One of them was
25, and other 24. Why?
25=5 2 , the next square is 6 2 =36, i.e. in 11 years.
24=4!, the next factorial is 5!=120, i.e. in 96 years.
A pupil divides 28 by 7 and receives as a result 13. His teacher asks him:
- How did you receive this result ?
- First I divide 8 by 7 and receive 1. Now 1 x 7 = 7 and I write:
Now I divide 21 by 7 and receive 3. Now I write:
The teacher asks him to check the result by
multiplication. The pupil answers:
- I execute 13 x 7 by the steps:
1) 1 x 7 = 7,
2) 3 x 7 = 21,
3) 7 + 21 = 28.
The teacher asks him to check the result by addition. The pupil answers:
- First I add 3 seven times and receive 21, then I add 1 seven times and receive 28.
A teacher of English was ill and a teacher of
mathematics replaced him. He began to compose a table of irregular verbs:
Then he said:
- Okay, I mark this form as x . Then it’s possible to compose the proportion:
Why do we hear a clatter of train wheels ?
Answer: Wheel has a form of a circle. An area of a circle is equal to p r 2 , so this square clatters.
Answer: Physicist thinks that 1 kilobyte = 1000 bytes, and programmer thinks that 1 kilometer = 1024 meters.
At a geometry lesson a teacher asks to represent the shortest distance between the two points A and B on a blackboard:
The teacher asks:
- Johnny, who taught you this ?
- My father, he is a taxi driver.