Puzzle Power
Fifth Class/Sixth Class
1) Two fathers and two sons went into a restaurant and had dinner which cost €15 in total. They each paid €5 for their meal. No tip was given and they received no change. Explain how this could happen.
2) Henry was offered two options when he agreed to work for 15 hours. FIRST OPTION: He could accept €8.50 per hour. SECOND OPTION: He could accept 1c for the first hour, 2c for the second hour, 4c for the third hour, 8c for the fourth hour and so on.
- A) Which option would give him the best payment for the 15 hours’ work?
- B) What is the difference in payment between the two options?
3) Jack cut a tree trunk in half. He then halved the pieces he cut and then he halved all those pieces. If the trunk was 8m long before Jack cut it, how long was each piece when he was finished? (There are two possible answers).
4) 
Draw one straight line across this watch face so that the numbers in each of the two parts add up to the same number.
Draw one straight line across this watch face so that the numbers in each of the two parts add up to the same number. 5) When asked my age, I replied that I was 35 years, not counting Saturdays and Sundays. What is my real age?
6) Add four numbers to make a total of 10. How many different ways can you do it?
7) Suppose 5 is your lucky number. To get a row of fives on your calculator, multiply 5 by 9. What do you get? Now, show all the numbers between 1 and 9 except 8 on your calculator. Multiply it by the answer of 9X5 and you get: 555555555555
- Now try to get a line of 1s, 8s and 7s.
8) What’s my age?
- Ask a friend to write the month in which he or she was born; 1 for January, 2 for February, 3 for March, and so on.
- Tell him or her to multiply this number by 5, then add 2, then multiply by 20, then add his or her age in years, and then subtract 40. Ask the person for his or her last answer.
- Solution: The last two digits of the answer give the age. The other digits give the month of birth.
- Example: 812 means the person is twelve years old and was born in August (Eight month).
9) Enter any 3-digit number on your calculator.
- Repeat the 3 digits to give a 6 digit number.
- Divide the number by 13.
- Divide the result by 11.
- Then divide by 7.
- Why does this always work?
- Now try it out with a 4-digit number :
- Repeat the 4 digits to give an 8 digit number.
- Divide the number by 73.
- Divide by 137.
- Discuss the outcomes.
- Try some numbers of your own.
10) Replace each question mark with +, -, x or ÷ to make this equation true.
4? 5? 3? 5 = 24
- Where would you put brackets so that the operations are done in the correct order?
11) A fire fighter was standing on the middle step of a ladder. When the smoke cleared, he went up 4 steps but the fire got worse so he climbed down 7 steps. As the smoke cleared again, he climbed up 8 steps to the top of the ladder. How many steps were on the ladder?
12) How many rectangles can you find in this illusion?
- The rectangles may be any size and squares are rectangles also!
| | | |
| | | |
| | | |
13) Jimmy wanted to send a message to his girlfriend while he was on holiday but he didn’t want anyone else to be able to read the message on his postcard.
-
|
14) A mother sends an email to her son with this coded message.
-
| |
15) Look at this optical illusion.
- Can you see grey squares appearing to move about the shape?
16) Look at this optical illusion.
-Can you see a young woman or an old woman?
17) Look at this illusion:
- Where do the steps lead to?
18) Passing Trains.
- A London train bound for Manchester leaves London at 12 noon travelling at 80 miles per hour while a Manchester train bound for London leaves Manchester at 1pm travelling at 90 miles per hour.
- Which train is nearer to London when they meet?
19) What seasonal message is this?
|
