Aptitude - Numbers - Discussion

Discussion Forum : Numbers - General Questions (Q.No. 69)
69.
n is a whole number which when divided by 4 gives 3 as remainder. What will be the remainder when 2n is divided by 4 ?
3
2
1
0
Answer: Option
Explanation:

Let n = 4q + 3. Then 2n = 8q + 6   = 4(2q + 1 ) + 2.

Thus, when 2n is divided by 4, the remainder is 2.

Discussion:
15 comments Page 1 of 2.

Kavi said:   1 decade ago
The simple form of these kind of sum is jus add 4+3=7 and 2n=2*7=14 which gives 2 as reminder.
(1)

Mayank agrawal said:   1 decade ago
What if I take n = 39(4*9+3)?

2n would be 78 and 78/4 will give me a remainder of 2.

How would you justify your answer now?

Vanitha said:   1 decade ago
I can't understand. Can you please explain it clearly?

Goutam said:   9 years ago
Please explain me.

Abhishek said:   8 years ago
n=4q+3,
therefore adjust to n=2(2q)+2+1.
n=2(2q+1)+1............................(1).
2n=8q+6.
2n=4(2q+1)+2...........................(2).
so from 1 and 2.

Answer is 2.
(1)

Ishwariya said:   8 years ago
I can't able to understand. Please explain it clearly.

Gautham said:   8 years ago
Why it can't be like this:
n = 4q+3..... eq-01.
2n = 4q+X...eq-02.

Putting eq-01 in eq-02,
2(4q+3) = 4q+X.
8q+6 = 4q+X.
X = 4q+6.
X = 2*(2q+3).

Remainder should be 3 I don't know why they are taking 2.
(1)

Kannan said:   7 years ago
Here;
n reminder is 3.
2n/4=?
substitute n value 3,
2(3)/4=6/4.
6/4=2.

Naina said:   7 years ago
Explain it clearly?

Deepika nair said:   7 years ago
I coulnt understand this concept. Could you please help me?


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