Official Quant thread for CAT 2013

its OA is D

its OA is D

@sbharadwaj how?
What is the remainder when the number 123123123.....123123 (300 digits) is divided by 99?
a) 18 b) 27 c) 33 d) 36
@abhishekj1991 said:
find a remainder of 2^133 divided by 133?
128?

E(133) = 108
2^108 mod 133 =
2^25 mod 133 = 2^4*2^21 mod 133 = 16*(125)^3 mod 133 = 16*(-5)^3 mod 133 = 128
@joyjitpal said:
What is the remainder when the number 123123123.....123123 (300 digits) is divided by 99?a) 18 b) 27 c) 33 d) 36
33
@abhishekj1991 said:
Use chinese reminder theorem or Eulers.
I used chinese..
2^133 / 133
Bifurcate 133 as 2 co-primes (or primes as well )
2^133/ 7*19
Solve them separately.,
2^133 % 7 = a (say) and 2^133 % 19 = b
Now,
7x + a = 19y + b.
Solve the equation for least possible number. That'll be your reminder 😃
Hope this helps..!!
@joyjitpal said:
alligation principle fails
My post in 3 words! :splat:
@raopradeep said:
what is the minimum value of the function |x-2|+|x-1|+|x+11| where x is real numbera)11B)13c)12d)14
13?
at x =1
Find the remainder when (123123123123..................300digits) is divided by 37.
@sbharadwaj pretty helpful !! thnx!!
@ajeetaryans said:
133 is a prime noand according to fermat theorema^p /p where P is a prime no remainder will be aso the answer is 2
sorry friend my mistake

if 133 = 19 * 7

then

first divide by 7

2 ^133 /7

= { 2 * 2 ^ 132 } /7

= { 2 * 8^44 } /7

= remainder is 2 when divide by 7

when divide by 19

reminder will be

2 ^ 133 /19 ->

- > (2^19)^7 / 19
-> 2^7 /19

128 /19 = 14 remainder

so now the answer

least no when divide by 7 gives remainder 2 and divide by 19 gives remainder 14 will be

7 m + 2 = 19 n + 14

m = { 19 n + 14 -2 } / 7
= { 19 n +12 } / 7

= 5 n + 5 / 7 (so put value of n such that it should be complete divisible )

n = 6 it will be complete divisible

so the remainder

= 19 n + 14
= 114 + 14
= 128
128 will be the remainder




@viewpt said:
33
approach batao bhai
@abhishekj1991 said:
Find the remainder when (123123123123..................300digits) is divided by 37.
16
@raopradeep said:what is the minimum value of the function |x-2|+|x-1|+|x+11| where x is real numbera)11B)13c)12d)14
13
@joyjitpal said:
What is the remainder when the number 123123123.....123123 (300 digits) is divided by 99?a) 18 b) 27 c) 33 d) 36
123123.................(300 digits)
=123(1+10^3+10^6+10^9+....................10^297)
taking modulo 99, we get
24*(1+10+1+10+1..........................+10)
24*550mod99
=24*55mod99
=33
@raopradeep said:what is the minimum value of the function |x-2|+|x-1|+|x+11| where x is real numbera)11B)13c)12d)14

13



@abhishekj1991 said:
Find the remainder when (123123123123..................300digits) is divided by 37.

37 * 3 = 111

111 * 9 = 999

so take an small example like

123123

123 * 1000 + 123
= { 123 (999 +1) + 123 } / 37

so remainder wil be {123 *2 } / 37

in same manner

when 300 digits total pairs are 100

( 123 * 100) / 37

= 12 * -11 /37
= -132 /37

= -21

= 16

so remainder will be 16








@bs0409 said:
123123.................(300 digits)=123(1+10^3+10^6+10^9+....................10^297)taking modulo 99, we get24*(1+10+1+10+1..........................+10)24*550mod99=24*55mod99=33
bro, can u explain d part in bold above?

take 123 common and then 10^297+................+ 10^0
@bs0409 bhai has written in different way ie. from10^0 to 10^297.