Making 9's
It’s not too hard to form the number 9 using three 3’s and any of the four standard
mathematical operations +, –, × and ÷. But can you come up with four different
solutions, each of which uses only one of the four operations? (Other standard
mathematical symbols can be used as needed.)
9
= 3 + 3 + 3
This brainteaser was
written by Derrick Niederman.