Make the number 21 using the numbers:(adsbygoogle = window.adsbygoogle || []).push({});

1, 5, 6, 7

you can use:

addition, subtraction, multipliaction and division

I promise you it is straight forward maths and NO tricks... you can only use each number once and you cant use say 15 (the 1 and the 5 together) and you cant do like 5^6 or anything.

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# Make 21

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