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OG Q194

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OG Q194

by kaf » Tue Mar 24, 2009 9:32 am
Please i would like someone to explain to me how this works.I found this question in OG

What is the units digit of (13)^4(17)^2(29)^3

I saw the explanation in OG but i would to find out if someone has
an alternative for solving this question quicker

thanks
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by DanaJ » Tue Mar 24, 2009 9:37 am
In order to find the units digit of this number you must first find the units digits of its components.
1. 13^4 - its units digit will be the units digit of 3^4 = 81 - so it's 1 for this one

2. 17^2 - its units digit will be the units digit of 7^2 = 49 - it's 9 for this number

3. 29^3 - its units digit will be the units digit of 9^3 = 729 - it's 9 again.

The units digit of the whole number will be the units digit of the product of the 3 units digit discovered above: 1*9*9 = 81 - units digit 1.
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