How many different two-digit numbers can you make using only the digits 2, 5, and 8? (You can use a digit more than once in a number to make numbers like 22).
Solution:
This problem can be solved in a number of ways. One way is to make a systematic list. Start with all the numbers with a 2 as the first digit, then all the numbers with a 5 and then all the numbers with an 8.
22
25
28
52
55
58
82
85
88
There are nine different two-digit numbers that you can make using only the digits 2, 5 and 8.