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Brainteasers

Puzzles to test mathematical skills, set by Anita Straker. Solutions below More brainteasers on www.tes.co.ukteacherbrainteasers

Age 7-12

SMALLEST NUMBER

What is the smallest number that leaves:

a remainder of 1 when divided by 2;

a remainder of 2 when divided by 3;

a remainder of 3 when divided by 4;

a remainder of 4 when divided by 5;

a remainder of 5 when divided by 6?

Age 11-14

A QUICK SNACK

5 coffees, 9 sandwiches and 7 pies cost pound;16.50.

3 coffees, 5 sandwiches and 4 pies cost pound;9.40.

What is the cost of 1 coffee, 1 sandwich and 1 pie?

SOLUTIONS

Smallest number 59

A quick snack 1 coffee, 1 sandwich and 1 pie cost pound;2.30. Let the cost of coffee be Pounds c, the cost of a pie be Pounds p and the cost of a sandwich be Pounds s. Then 5c + 9s + 7p = 16.5.

3c +5s + 4p = 9.4. Subtracting one equation from the other gives: 2c + 4s + 3p = 7.1. Subtracting from the second equation gives c + s + p = 2.3.

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