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 4 of 4.
Radha gayathri said:
5 years ago
Formula: dividend = divisor * quotient + remainder.
Divisor=5, reamainder=3.
5*q+3.
(5*q+3)^2/5.
Assume q as 1,
(5+3)^2/5,
(8)^2/5,
64/5.
And the remainder is 4.
Divisor=5, reamainder=3.
5*q+3.
(5*q+3)^2/5.
Assume q as 1,
(5+3)^2/5,
(8)^2/5,
64/5.
And the remainder is 4.
(1)
Karthik pyati said:
5 years ago
1step: to add 5+3=8 den divide by 5, will give remainder as 3, then square the remainder number 3 i.e(3^2)=9, when dividing the no 5 & the remainder will be 4.
(1)
Pema said:
5 years ago
Thank you @Neha Nagar.
Kamila Banu said:
4 years ago
= 3 * 3 = 9.
= 9 - 5 = 4.
= 9 - 5 = 4.
Pavishka said:
4 years ago
We assume the nearest value + reminder.
i.e 5 + 3 = 8
8/5 = 1 (reminder=3)
And square of 8 is 64
64/5 = 12
The reminder is 4 so,
ans = 4.
i.e 5 + 3 = 8
8/5 = 1 (reminder=3)
And square of 8 is 64
64/5 = 12
The reminder is 4 so,
ans = 4.
(6)
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)
Timothy Mayanja said:
2 years ago
I don't understand the following step,
(25k^2 + 30k + 9).
Please explain to me in detail.
(25k^2 + 30k + 9).
Please explain to me in detail.
(2)
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