Aptitude - Numbers - Discussion

I have for the given problem.

4*5*1= 20 that is unit digit =0;

But for (264)^102*(264)^103 we need to get answer as 4*4 = 16 unit digit as 6,

But in test book they given answer as 0,

How it is please explain me?

On the basis of cyclicity rule we easily find the unit digit .

4*5*1 = 0.
4^1 =4 5^1 =5 1^1=1.
4^2 =6 5^2 =5 1 cyclicity is 1.
4^3 =4 5 cyclicity is 5.
Cyclicity of 4 is 2.

Then 4^1793 divide 1793/3 = 1 4^1 = 4 as on...

Finally 4*5*1 = 0.

Find unit digit of 1^1!+2^2!+........+80^80.

What is a unit digit? please anyone explain me.

As well say for this: 31.999*12.001*17.5001.

What mean by unit digit?

What is the unit digit of 7^63* 3^57 * 6^41 ?

Look Friends its Simple:

Just take the last digit of number and last digit of power.

1). Here given is 6374^1793 means you should take 4^3 which is 64
means for 4^3 (4*4=16 and 16*4 is 64 or 6*4 is 24 whose unit digit is 4(remember for finding unit digit always take last digit after multiplication).

2). 625^317 means 5^7 here remember any power to 5 will always have 5 as its unit digit. So here the no is 5.

3). 341^491 means 1^1 is always 1 in its unit digit.

So from 1, 2, and 3 we got three numbers ie 4, 5, 1.

Now multiply these numbers and take the last digit of the product which will be your answer(4*5*1=20).

So 0 is your answer.

6374 U.D is 4.
625 U.D is 5.

341 U.D is 1.
4*5*1=20.

20 U.D is 0.
Answer is zero.

If we have to find tens digit then how we find and the expression is same { (6374) ^1793 x (625) ^317 x (341^491) }?