Thread: Find last two digit of a number

Find the last two digits of

so:




So last two digits is M+ N

I dont really know how to continue...

Any help would be appreciated
Thanks in advance

By calculating and we can see that

and

.

Therefore,







Answer is 48.

Originally Posted by icemanfan

Answer is 67.

thanks

But answer should be ?

Is there any simpler way to compute this without calculating 3^20?

Originally Posted by firebio

thanks

But answer should be ?

Is there any simpler way to compute this without calculating 3^20?

You are correct, I made a silly mistake at the end. If you can determine that without actually calculating , then yes. Personally, I don't know how you would do it. In most of these types of problems, the cycle is much shorter than 20.

Originally Posted by icemanfan

You are correct, I made a silly mistake at the end. If you can determine that without actually calculating , then yes. Personally, I don't know how you would do it. In most of these types of problems, the cycle is much shorter than 20.

i see.. i asked because this was a test question and calculating 3^20 seems a bit harsh.

Thanks so much.