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 ?
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.
Bindu said:
6 years ago
Assume n to be any number such that when it is divided by 4 we should get 3 as R.
So let n be 15 (when 15/4, R=3, condition satisfied as per in the given question).
Therefore 2n will be 30. (when 30/4, R=2, the required answer).
So let n be 15 (when 15/4, R=3, condition satisfied as per in the given question).
Therefore 2n will be 30. (when 30/4, R=2, the required answer).
(5)
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.
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)
Shweta said:
7 years ago
Lt quotient be q and R be remainder.
n=4q+3 ---> eqn(1)
2n=4q+R ---> eqn(2)
therefore, putting eqn(1) in eqn (2);
2(4q+3) = 4q+R.
8q+6 = 4q + R,
let q=1,
4+6=R,
10 = R,
when 10 is divided by 4;
R=2.
n=4q+3 ---> eqn(1)
2n=4q+R ---> eqn(2)
therefore, putting eqn(1) in eqn (2);
2(4q+3) = 4q+R.
8q+6 = 4q + R,
let q=1,
4+6=R,
10 = R,
when 10 is divided by 4;
R=2.
(2)
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.
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)
Tejas said:
4 years ago
If n=19 then 2n = 38.
2n/4=38/4 (here remainder is 2) =19/2 (here remainder is 1).
Why does remainder change for the same fraction? Please explain me.
2n/4=38/4 (here remainder is 2) =19/2 (here remainder is 1).
Why does remainder change for the same fraction? Please explain me.
Naina said:
7 years ago
The equation be like;
n=4*q+3 (let us assume q=1)
n=4+3
n=7.
Next equation is;
2n=4*q+x (q=1,assumed).
2(7)=4+x,
14/4 = x,
The remainder 2.
n=4*q+3 (let us assume q=1)
n=4+3
n=7.
Next equation is;
2n=4*q+x (q=1,assumed).
2(7)=4+x,
14/4 = x,
The remainder 2.
(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?
2n would be 78 and 78/4 will give me a remainder of 2.
How would you justify your answer now?
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)
Kannan said:
7 years ago
Here;
n reminder is 3.
2n/4=?
substitute n value 3,
2(3)/4=6/4.
6/4=2.
n reminder is 3.
2n/4=?
substitute n value 3,
2(3)/4=6/4.
6/4=2.
Deepika nair said:
7 years ago
I coulnt understand this concept. Could you please help me?
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