Math CentralQuandaries & Queries


Question from Kim, a parent:

Can you help me with the following problem:

Find the number from the following clues:

A) is is a 3 digit even whole # divisible by 5
B} Each digit is different
C) Its hundreds digit is greater than its tens digit
D) It is less that 400, divisible by 3, and has only 1 odd digit.

I know that the last digit is 5. I am confused with c & D as it has to be in t
he 200 as there is only 1 odd digit but if the tens digit is greater than the 100's

I am lost.

Please help

Hi Kim,

Since the number is divisible by 5 its units digit must be 5 or 0. Since it is also even its units digit must be divisible by 2. Thus the units digit is 0. Thus the number looks like


where p is the hundredth digit and q is the tens digit.

Since the number is less than 400 p is 1, 2 or 3.

Can you complete the problem now?

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