Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 90)
90.
What is the unit digit in(795 - 358)?
Answer: Option
Explanation:
Unit digit in 795 = Unit digit in [(74)23 x 73]
= Unit digit in [(Unit digit in(2401))23 x (343)]
= Unit digit in (123 x 343)
= Unit digit in (343)
= 3
Unit digit in 358 = Unit digit in [(34)14 x 32]
= Unit digit in [Unit digit in (81)14 x 32]
= Unit digit in [(1)14 x 32]
= Unit digit in (1 x 9)
= Unit digit in (9)
= 9
Unit digit in (795 - 358) = Unit digit in (343 - 9) = Unit digit in (334) = 4.
So, Option B is the answer.
Discussion:
36 comments Page 3 of 4.
Naveen said:
1 decade ago
Unit digit should not show in negative digits. So actually total digit in 7^95 is 343.43-9=34.
So 4 is the correct answer.
So 4 is the correct answer.
Premnath said:
6 years ago
How come we take,
7^95 = 7^92+7^3?
What happens if we take, 7^95 = 7^93 + 7^2, How to solve this? Please tell me.
7^95 = 7^92+7^3?
What happens if we take, 7^95 = 7^93 + 7^2, How to solve this? Please tell me.
Lara said:
1 decade ago
Idea is simply to express the given number, in such a way that unit's place should be 1. i.e., 7^4 is 2401 and 3^4 is 81.
Ranga said:
6 years ago
Because 6 is an actual difference but negative come to take 10 value.
i.e means 10-6 = 4 is the right answer.
i.e means 10-6 = 4 is the right answer.
(1)
Rushikesh Patil said:
4 years ago
= 7(90-5)-3(60-2)
= 7(90)-7(5)-3(60)-3(2)
= 7(9-5)-3(6-2)
= 7(4)-3(4)
= 4(4).
Then, the answer is 4.
= 7(90)-7(5)-3(60)-3(2)
= 7(9-5)-3(6-2)
= 7(4)-3(4)
= 4(4).
Then, the answer is 4.
(10)
Snehasish said:
6 years ago
To all values of n = (x*m-a*m) is divisible by (x- a) thus 7-3 = 4 is the Ans.
Kala said:
1 decade ago
7^3=343 and 3^2=9
difference 343-9
ans 4
How? Please explain every step.
difference 343-9
ans 4
How? Please explain every step.
(1)
LINGANAYAKA said:
8 years ago
I'm not understanding it, Someone please help me to get it.
Jot said:
1 decade ago
My answer is 6. But how is it 4? Please elaborate clearly.
(1)
Ali N said:
9 years ago
@Cradlerian.
Thanks for your solution.
Thanks for your solution.
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