Q. A group of people is sitting around a round table. They give a coffee break. When they return to the table after the break, they sit down randomly. Interestingly, they notice that the six closest persons sitting next to each one of them (three to the left, and three to the right) are completely different from the six closest persons in the previous setting.
Q. You are playing a game with your friend. Your friend chooses three of the numbers among (1, 2, 3, 4, 5, 6, 7, 8, 9). You will call four numbers in each turn, and he will tell you how many of them are among the chosen numbers.
In order to guarantee to find these numbers in all cases, how many turns are needed?
Q. In a game, the 1st person tosses a coin. If the outcome is head, he throws a dice and the result is recorded as his score and he gets one more chance to toss the coin. If the outcome is tail then the next person gets a chance to toss the coin. What is the probability that a person scores 35 points after 6 tosses in this game?
Option
a) (1/32)(1/6)^5
b) (1/32)(1/6)^6
c) (1/64) (1/6)^6
d) (1/64) (1/6)^5
Q. My friend owns a horse-driven carriage. It was found that the fore wheels of the carriage make four more revolutions than the hind wheel in going 96 feet. However, it was also found that if the circumference of the fore wheel was 3/2 as great and of the hind wheel 4/3 as great, then the fore wheel would make only 2 revolutions more than hind wheel in going the same distance of 96 feet. Can you find the circumference of each wheel?
Q. Arrange the ten digits 0 to 9 in three arithmetical sums, using three of the four operations of addition, subtraction, multiplication, and division, and using no signs except the ordinary ones implying those operations. Here is an example to make it quite clear:
3 + 4 = 7
9 - 8 = 1
5 X 6 = 30
But, the example is not correct, as the number 2 has not been used and the number 3 has been used twice. Can you come up with a valid solution?
Q. The ages of Old and Young total 48. Old is twice as old as Young was when Old was half as old as Young will be when Young is three times as old as Old was when Old was three times as old as Young. How old is Old?
Q. Two towns are linked by a railroad. Every hour on the hour a train leaves each town for the other town. The trains all go at the same speed and every trip from one town to the other takes 5 hours. How many trains are met by one train during one trip?
Q. My room has a square window of 4 feet across and 4 feet down. I decided to get only half the area of the window painted. Even after the painting, I found that the clear part of the window still remained a square and still measured 4 feet from top to bottom and 4 feet from side to side. How is it possible?
Q. Four whole numbers - a, b, c and d.
such that -
1. ( a + b + c + d ) is a perfect square
2. ( a + b ), ( a + c ), ( a + d ), ( b + c ) , ( b + d ) and ( c + d ) are also each a perfect square. What are the smallest values for a, b, c and d?
Students attend our lectures, not because the mathematics we teach ‘makes lots of fun’ for us, but because they believe they can learn some essential knowledge from us. And each of our young students has only one life to live. We should therefore be a
H. Behnke
Mathematics has 25%formulas, 25%proofs and apply 25%thinking and 25%efforts.
In real life situations proofs are nothing but already existed stories(we know the solutions from all experienced people).
formulas are nothing but goals. we have so many goals b