Question

With the digits 1 up to 9, you must make 100, using the following rules:Each digit must be used exactly once.The only allowed operation is addition.Two single digits may be combined to form a number (so, for example, 2 and 4 may be combined to 24 or 42).Two single digits may be combined to form a fraction (so, for example, 2 and 4 may be combined to 2/4 or 4/2).

Answer 1

This puzzle is some what tricky and not easy.  It takes quite a while with fractions using reasonable logical and systematic steps.

I have been able to form these following answers.  Perhaps there are more:


     7            4
31 ---  +  9  ----  + 56   = 100
     2            8

     4            7
31 ---  +  9  ----  + 56   = 100
     8            2

     7            4
56 ---  +  9  ----  + 31   = 100
     2            8

     4            7
56 ---  +  9  ----  + 31   = 100
     8            2

51 + 36 + 9 + 7/2 + 4/8  = 100

51 + 39 + 6 + 7/2  + 4/8  = 100

56 + 39 + 1 + 7/2 + 4/8 = 100

31 + 56 + 9 + 7/2 + 4/8  = 100

31 + 59 + 6 + 7/2 + 4/8  = 100
 
59 + 36 + 1 + 7/2 + 4/8  = 100