Number System - Questions & Discussions

but bro cannot it b like dis:

51/7=2 remainder i.e. 2 to the power 203..again 2 to the power 3 * 2 to the power 200 which again if divided by 7 i.e. 2 to the power 3 divided by 7 will give remainder 1...so, final answer 1...isnt it a correct ans??...kindly xplain...thnks in advance...
CHEERS!!


i dint quite get what u meant?? thoda numbers leke explain karoge?

Hi everyone!
Find the remainder when 55^190 is divided by 153?
The answer key says 120 but I'm getting 118 as the answer.
Where did I go wrong


153=17*9

55%9=1

so rem will be of the form 9k+1. 118 hi hoga bhai. 120 isnt fitting. u r correct.

What is the remainder when 20^51^97 is divided by17?

shrutishrma113 Says
What is the remainder when 20^51^97 is divided by17?



Is the answer 3?

The answer is 10.

Getting 10.

51^97 ka remainder by 16 = 3
so 20^3 ka remainder by 17= 10

shrutishrma113 Says
What is the remainder when 20^51^97 is divided by17?

20^51^97 /17

51^91 leaves rem of 3 by 16

hence expression reduces to 20^3/17

so remainder = 10

I have a doubt.Where did you get that 16 from?

shrutishrma113 Says
I have a doubt.Where did you get that 16 from?


Euler no of 17

= 17 (1- 1/17) = 16
now apply fermat.
shrutishrma113 Says
What is the remainder when 20^51^97 is divided by17?



getting 10.

Thanks.Got it 😁

Ya ..the remainder shud be 10..

Hi everyone!
Find the remainder when 55^190 is divided by 153?
The answer key says 120 but I'm getting 118 as the answer.
Where did I go wrong


Answer is coming 118 only..maybe the OA u have is erroneous..
shrutishrma113 Says
I have a doubt.Where did you get that 16 from?

Life of a CAT aspirant: CoPrimes, Euler's Number and Fermat's theorem

This may help you 😃

@Godschild : Thanks for the link :)
Find the total number of natural numbers n for which 111 divides (16^n)-1, Where n is less than 1000.

@Godschild : Thanks for the link :)
Find the total number of natural numbers n for which 111 divides (16^n)-1, Where n is less than 1000.


111 = 37 * 3

mod3 = 0 (for all n)

E = 36

So 16^36mod37 = 1
Now we need to check if there is a lower power of 16 other than 36 that gives the remainder 1 when divided by 37. So we check for factors of 36 as possible powers.

16^2mod37 = -3 --> 16^4Mod37 = 9 ---> 16^6mod37 = 10

16^3mod37 = -11 ---> 16^9mod37 = -110 = 1

So (16^9 - 1)mod37 = 0

So for all n = 9k, 111 divides 16^n-1

From 1-1000. there are 111 such no.s
The number of positive integers valued pairs (x, y) satisfying 4x - 17y = 1 and x
(1) 59 (2) 57 (3) 55 (4) 58

Please explain the answer. I am getting 58.

My method:

y = (4x - 1)/17

Now, 1000/17 gives 58 and 14 remainder.
The number of positive integers valued pairs (x, y) satisfying 4x - 17y = 1 and x
(1) 59 (2) 57 (3) 55 (4) 58
Please explain the answer. I am getting 58.


It should be 59.

4x-17y = 1 => 4x = 17y+1
=> 4x = 16y + y + 1
It means, when y leaves remainder by 4 as 3, 17y+1 is divisible by 4.
So, y can be 3, 7, ....
Now, 4000/17 = 235.xx
So, maximum values y can take = 236/4 = 59
The number of positive integers valued pairs (x, y) satisfying 4x - 17y = 1 and x
(1) 59 (2) 57 (3) 55 (4) 58

Please explain the answer. I am getting 58.

My method:

y = (4x - 1)/17

Now, 1000/17 gives 58 and 14 remainder.


I m gtng 59 as my ans...as 1st pair which satisfies the above eq vl be(13,3)...now adding (17,4) we will get next pair and thus a total of 59 pairs ..last being(999,235).

Can any one please help me out ?

I want to know how to go about questions where we have to find the remainder when a single (or multiple) digit/s are repeated is divided by a number

:-(:-(
Can any one please help me out ?

I want to know how to go about questions where we have to find the remainder when a single (or multiple) digit/s are repeated is divided by a number