Aptitude - Numbers - Discussion

As in 6374 = unit digit is '4'
in 625 = unit digit is '5'
in 341 = unit digit is '1'.

Now just multiply all the digit units =4 * 5 * 1=20
In 20, the unit digit is '0'.

Again,
In the power of 6374 i.e,1793 = unit digit is '3',
In the power of 625 i.e, 317 = unit digit is '7',
In the power of 341 i.e, 491 = unit digit is '1',
Now multiply all the digit units = 3*7*1=21.
In 21, the unit digit is '1'.
Hence,
The required unit digit is, 0^1.
= 0 (answer).

Thanks @Seema.

Nice explanation, Thanks all.

Thanks @Seema.

Thanks for the answer @Vasudevan.

Thanks @Hola.

Simply, We have to take last digit of every number so by taking last number as 4, 5, 1. Now multiply these 4*5*1=20 so now take last digit of answer so it is 0 (zero).

In short method,

6374^1793.
1793/4=448, remainder 01.
So answer is 4^1(take the last digit in 6374).

In 625^325.
325/4=79remainder 01.
So answer is 5^1.

In 341^491.
491/4=122remainder 3.
So 1^3.

Finally;
4^1*5^1*1^3=20.
In 20, take last digit 0 is the answer.

Simply, We have to take last digit of every number so by taking last number as 4, 5, 1. Now multiply these 4*5*1=20 so now take last digit of answer so it is 0 (zero).

Consider this:

For,x=Odd, the unit place for 4^x is 4. The unit place for 5^x is 5, The unit place for 1^x is 1.
and x=Even, the unit place for 4^x is 6. The unit place for 5^x is 0, The unit place for 1^x is 1.

=>unit place means the digit present at the one's place(rightmost digit) of a number.