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"1. What is the four-digit number in which the first digit is one-fifth the last, and the second and third digits are the last digit multiplied by 3? (Hint: The sum of all digits is 12.)"

I don't understand how they got the answer to this one; it makes no sense to me at all.

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The only digit that can be 1/5 the last would be 1 if the last were 5 (because 2/10 doesn't work, 10 isn't a single digit and they need to be whole).

From there, digits 2 and 3 are the last (5) multiplied by 3. So: 1155. Add those up: 1 + 1 + 5 + 5 = 12.

I think. :)

I get it now. Was trying to multiply them individually, which doesn't work at all. Thanks. =D

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