Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 10)
10.
What is the unit digit in {(6374)1793 x (625)317 x (341491)}?
Answer: Option
Explanation:
Unit digit in (6374)1793 = Unit digit in (4)1793
= Unit digit in [(42)896 x 4]
= Unit digit in (6 x 4) = 4
Unit digit in (625)317 = Unit digit in (5)317 = 5
Unit digit in (341)491 = Unit digit in (1)491 = 1
Required digit = Unit digit in (4 x 5 x 1) = 0.
Discussion:
123 comments Page 10 of 13.
Raj said:
8 years ago
Thanks @Jhansi.
Harshal said:
8 years ago
In simpler manner for 4^x.
For,x=Odd unit place is 4.
and x=Even unit place is 6.
For,x=Odd unit place is 4.
and x=Even unit place is 6.
Sabu said:
7 years ago
Understand the answer, Thank you, @Seema.
Himanshi said:
7 years ago
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.
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.
Ahankar said:
7 years ago
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).
Arpitha M said:
7 years ago
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.
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.
Hola said:
7 years ago
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).
Mrunal said:
7 years ago
Thanks @Hola.
Nafeesa said:
7 years ago
Thanks for the answer @Vasudevan.
Keerthinayak said:
6 years ago
Thanks @Seema.
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