Aptitude - Numbers - Discussion
Discussion Forum : Numbers - General Questions (Q.No. 31)
31.
On dividing a number by 5, we get 3 as remainder. What will the remainder when the square of the this number is divided by 5 ?
Answer: Option
Explanation:
Let the number be x and on dividing x by 5, we get k as quotient and 3 as remainder.
x = 5k + 3
x2 = (5k + 3)2
= (25k2 + 30k + 9)
= 5(5k2 + 6k + 1) + 4
On dividing x2 by 5, we get 4 as remainder.
Discussion:
37 comments Page 3 of 4.
Neha yadav said:
10 years ago
In the above equation 30K come by algebra formula i.e. (a+b)^2 = a^2+2ab+b^2.
(1)
Purushothaman said:
1 decade ago
Exclusive me, I have little doubt how could come to 30 k please explain me.
Narendra said:
1 decade ago
As take remainder that is 3 square it 9 divide it by 5 answer will be 4.
Jaisree said:
4 years ago
We can square the reminder and divide it by 5.
3^3 = 9.
9/5 = 4 (rem).
3^3 = 9.
9/5 = 4 (rem).
(16)
Aparna said:
1 decade ago
How could 30k has come in this answer please anyone explain me.
Kiran said:
1 decade ago
Let the num is 3. Then square of 3 is 9 so 9/5 remainder is 4.
Balaji Shinde said:
1 decade ago
5+3 = 8.
So square of 8 is 64.
If 64/5 remainder will be 4.
So square of 8 is 64.
If 64/5 remainder will be 4.
Rajesh rao.v said:
2 decades ago
X = 5+3 = 8 square of 8 = 64 then 64/5 remainder is 4.
(1)
Bhavani said:
8 years ago
@Rajesh Rao.
You explained in a easy way Thank you !
You explained in a easy way Thank you !
(1)
Amit said:
1 decade ago
x/5 = 3.
Square of (x/5)/5 = 9/5 = 4.
Square of (x/5)/5 = 9/5 = 4.
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