Without using addition, make five 6s to equal 30.
Without using addition, make six 7s to equal 42.

The calculations should be exact (no rounding functions). Any common symbols or operators other than addition are allowed.

Replacing addition with subtracting a negative is NOT a solution.

POSSIBLE SOLUTIONS:    ==so far

WITH  FIVE DIGITS :
30=6/6 * (6*6-6)        or  6*(66/6-6)
and
42=7/7 * (7*7-7)       

WITH  six DIGITS :
30=(sqrt(6*6)) /6 * (6*6-6)       or 6!/(6-6/6-6/6)!
and
42=(sqrt(7*7) /7) *( 7*7-7)       or  7!/(7-7/7-7/7)!

WITH four DIGITS :
30=6* (6-6/6)         
42=7*(7-7/7)

WITH  three DIGITS :
30=  6*6-6
42=7*7-7

there are probably more ....

Ed

Edited on December 14, 2009, 2:01 pm

Posted by Ady TZIDON on 2009-12-14 13:44:57