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#18 The arithmetical two-step
Set by Peter Rowlett
You must take two steps to get from a given number to make 10. Each step must change the number by adding, subtracting, multiplying by or dividing by a number from 1 to 9. (Multiplying or dividing by 1 isn’t allowed as it doesn’t change the number.)
For example, starting with 35, one way would be to first divide by 7 then add 5.
Can you take two steps to get from 42 to 10?
Is it possible to get to 10 in two steps from all the numbers 11 to 30?…
