Question

When 3n is divided by 7, the remainder is 4. What is the remainder when 2n is divided by 7?

Help, a bit confused here...again. Please guys

Answer 1

when 3n is divided by 7 its not always gives 4
eg..
n = 3 or 4
its gives 2 and 5

Answer 2

@nirmalnema wait, so, ya, if 3n is divided by 7 and the remainder is 4, so that means n = 6?

Answer 3

i dont said that it doesn't give ..
i said it not always correct

Answer 4

Yes, n would = 6

As 6*3 = 18

7 goes into 18 2 times and the remainder is 4

Answer 5

@nirmalnema ahh ok, but i got a bit of your point. I tried n = 6 (trial&error) and did all the equation stuff and I got 5 as the remainder. I have answer key here though

Answer 6

How did you get 5 lol ._.

Answer 7

@tHe_FiZiCx99 the question asked for the remainder. Since the divided is 2n and the divisor is 7, ---- 2(6) divided by 7 is equal to 1 r 5. =))

Answer 8

yup its correct...

Answer 9

ah ok btw thanks for your point :)

Answer 10

your welcome... = P

Answer 11

Oh I was taking about 3n divided by 7 xD

Answer 12

you may lessen the effort during trial/error if u check both positive and negative remainders :-
3n = 4 (mod 7)
3(-1) = 4 (mod 7)
n = -1 (mod 7)

=>
2n = -2 (mod 7) = 5 (mod 7)