2014 AMC 8 Problems/Problem 22
Problem
A -digit number is such that the product of the digits plus the sum of the digits is equal to the number. What is the units digit of the number?
Solution
We can think of the number as , where a and b are digits. Since the number is equal to the product of the digits () plus the sum of the digits (), we can say that . We can simplify this to , and factor to . Dividing by , we have that . Therefore, the units digit, , is
See Also
2014 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by Problem 21 |
Followed by Problem 23 | |
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