Question 1194295: Laura's iphone requires a 6-digit unlock code using the numbers 0-9 on the keypad. How many different codes could Laura use for her phone?
Found 2 solutions by math_tutor2020, ikleyn:
Answer by math_tutor2020(3817)   (Show Source):
You can put this solution on YOUR website!
Answer: 1,000,000
Delete the commas if needed.
Reason:
There are 10 items in the set {0,1,2,..,9} and 6 slots. That gives 10^6 = 1,000,000 (one million) different six-digit codes where repeat digits are allowed.
If you wanted, you can consider a smaller subproblem. Imagine you had only 2 slots to work with rather than 6. Then picture a 10 by 10 table to show the 10*10 = 100 two-digit codes possible. Extend this idea out to 6 digits and that's why we multiply.
We shorten the repeated multiplication by using exponents
10^6 = multiply out 6 copies of "10"
Answer by ikleyn(52786)  (Show Source):
You can put this solution on YOUR website! .
If repetition of the digits is allowed in the code, (which you may assume, since the problem
does not prohibit it), then in each of the 6 positions there are 10 possible digits from 0 to 9, inclusive.
In 6 positions, it gives  = 1,000,000 possible codes (one million), in total. ANSWER
Solved and explained.
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