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 9 of 13.
RADHAKRISHNAN E said:
9 years ago
yes you are good @Seema.
Sravanthi said:
9 years ago
@Seema, you have done a good job.
Nataraj said:
9 years ago
Please give the clarity to solve the problem.
Harikrishna said:
9 years ago
Your method is very easy. Thank you @Ramya.
NIDHIN M Z said:
9 years ago
Unit Digit of Base, Powers, Unit digit of the product.
0, 1, 5, 6, any powers, same digit.
3, 7, 9, power exactly divisible by 4, 1.
2, 4, 8 " 6.
So in this problem: {(6374)^1793 x (625)^317 x (341)^491)}.
= (6374)^1793 unit digit is 4.
Apply the above rule: Divide 1793 by 4, we get remainder as 1.
Take the remainder of the power of unit digit's i.e. 4^1.
So we get (6374)^1793 = 4. For (625) ^317 same digit as the unit digit.
So we get (625)^317 = 5. For (341)^(491) the same digit as the unit digit.
So we get (341)^(491) = 1.
Finally (4 * 5 * 1) = 20.
Thus unit digit is 0 = Answer.
0, 1, 5, 6, any powers, same digit.
3, 7, 9, power exactly divisible by 4, 1.
2, 4, 8 " 6.
So in this problem: {(6374)^1793 x (625)^317 x (341)^491)}.
= (6374)^1793 unit digit is 4.
Apply the above rule: Divide 1793 by 4, we get remainder as 1.
Take the remainder of the power of unit digit's i.e. 4^1.
So we get (6374)^1793 = 4. For (625) ^317 same digit as the unit digit.
So we get (625)^317 = 5. For (341)^(491) the same digit as the unit digit.
So we get (341)^(491) = 1.
Finally (4 * 5 * 1) = 20.
Thus unit digit is 0 = Answer.
Apurva Raj said:
9 years ago
Anybody can find the remainder of this question (5^625) /7?
Reshma said:
9 years ago
Thank you @Nidhin M Z.
Hemant said:
9 years ago
How - (5)^317 = 5?
I solved - (5^2)^158 * 5 it gives unit digit 0.
I solved - (5^2)^158 * 5 it gives unit digit 0.
Sowjanya said:
8 years ago
There is simply way to get this answer.
{(6374)1793*(625)317*(314 )491)}.
Unit place is the last number.
4 * 5 * 1 = 20.
Last digit is 0.
{(6374)1793*(625)317*(314 )491)}.
Unit place is the last number.
4 * 5 * 1 = 20.
Last digit is 0.
Teju said:
8 years ago
Thanks @Sowjanya.
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