Need some help with a question regarding number sequences

Joxu

New member
Joined
Mar 25, 2020
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1
At which values of n is the decimal number 12n34n567n89n divisible by
a) 3
b) 6

An explain would also be appreciated.
I also accidentally marked this as solved, so don't mind that.
 
Last edited:

Dr.Peterson

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Joined
Nov 12, 2017
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6,663
The rule for divisibility by 3 is that the sum of all the digits must be a multiple of 3. For example, to test whether 18453 is divisible by 3, we add 1+8+4+5+3 = 21, which is a multiple of three, so 18453 is also.

So what value of n will make that happen?

Once you've answered that, consider that any multiple of 6 is a multiple of both 3 and 2.

Let us know what you find, so we can continue to help if needed.
 
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