A broken calculator has only the keys:
+(addition), -(subtraction), /(division), x(multiplication), =(equals)
It is a simple calculator that can do one binary operation at a time.
The only functional digit is 7.

How is it possible for 34 to appear in the readout in the fewest number of keystrokes?

Notes:

1. Performing as many operations as possible is allowed.

2. The digit 7 may be reused, that is expressions like 777x77 or, 7777+7 in a given operation is allowed.

10 keystrokes

First operation, 6 keystrokes: 777/7=
result: 111
Second operation, 4 additional keystrokes -77 =
result: 34

Posted by Dej Mar on 2013-07-31 12:21:01