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Brainteasers

Make 100

The ancient Zunarians used to write all their numbers using just one digit.

They wrote the number 100 using five ones like this: Make 100 using five twos and any of the symbols +, - , x, V and C.

Now try five threes, five fours and five fives.

Treasure hunt

The pirates have found an old scroll.

On it is a map covered in squares numbered as shown below. However, the lower part of the grid has faded.

The scroll says that the treasure is in square number 500. In which row and which column is the treasure?

Make 100 (Ages 10 to 14) Possible solutions are

SOLUTIONS Treasure hunt (Ages 9 to 13) The treasure is in row 125, column D. You could solve this problem by counting, but it is better to recognise that the sequence in column E is of the form 4n + 1, where n is the row number (even numbered rows do not exist). 501 = 4n + 1, where n = 125, so 500 is in column D in row 125.

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