Number System - Questions & Discussions


@sonamaries7 said: someone plz help solving the qs:what is the remainder when 67raised to the power of 53 is divided by 101? (67^53 divided by 101)Plz provide detailed solns ...Thanks
Hi,

Is the Answer 2?

@[419941:Enceladus] I cannot undersatnd how 6X mod 49 gives 41 could you please elaborate

what is the answer of (67^53)/101??? is it 86?

@[547670:koyal1990] What is your approach . My answer is -86 or say 15.

Can you please explain your approach.

Thanks

@[532679:devendersnegi]- 101 and 67 being co primes, i used euler's method. euler's no of 101 is 100. so we can write the number as [67^100]^1/2 (which is 50) *67^3. by indices rules, it boils down to 67^53. now the 1st part remainder is 1, next part was a lil calculation heavy. i tried to minimize the cal by taking 67^2 which is 4489 and dividing it by 101. this gives a remainder of 45. then 45*67 divided by 101 gives 86. i am not very sure of the method though. how did u solve it n what is the ans?

@[515126:kejriwalsonal1]:thanx:)

hey all.. im a little new to eulers method and chinese remainder method.. So I would be obliged if anyone can explain what the following statements mean.. along with the approach to get the final answer !


(36^41) mod 7 = 1
(36^41) mod 11 = 3

also.. fyi.. i found this in this thread..
http://www.pagalguy.com/forums/quantitative-ability-and-di/number-system-questions-and-discussions-t-43728/p-1642745?page=3

thank you ! :)

Plz help in solving dis ques...............

How many numbers less than 500 will have digit sum equal to 5???

@Rshmi05 said:

Plz help in solving dis ques...............

How many numbers less than 500 will have digit sum equal to 5???

Take No. of nos. having digit sum 5 from 1) 20 to 30______ 2)40 to 50_______ 3)60 to 80

You'll get Your ans.

I have counted and it came around 20.

But options are

39,72,55 ,81

@Rshmi05 said:

Plz help in solving dis ques...............

How many numbers less than 500 will have digit sum equal to 5???

method 1 :

single digit - 5

two digits :

a + b = 5 or 14

a + b = 5 --> 50,14,41,23,32

a + b = 14 --> 77,68,86,59,95

three digits :

a + b + c = 5 or 14 or 23

count and find the numbers

method 2 :

digit sum is nothing but divisibility by 9 .. so all number of form 9k +5 will have digit sum 5

so 500/9 = 55 .

so answer is 55



@[169132:naga25french] .................ok..........got it...thanks a lot..............

@[169132:naga25french]- why is digit sum divisibility by 9? cud u please explain the second method plz? TIA...

P is a prime number greater than 37.then the largest number that will always divide (P-1)X(P+1) is


a) 32 b) 16 c) 8 d) 4 e) 24
@lopagargg said: P is a prime number greater than 37.then the largest number that will always divide (P-1)X(P+1) is
a) 32 b) 16 c) 8 d) 4 e) 24
it will be 24

@gs4890 said:
it will be 24
approach pls

Take the least prime number greater than 37, which is 41
P = 41
(p-1)*(p+1) = 40*42 = 4*10*2*21 = 2*2*2*5*2*3*7 = 2^4*3*5*7
32 = 2*16 = 2^5
24 = 2*12 = 2*2*2*3 = 2^3*3

m and n are natural number with m x n =160000.if neither m nor n is a multiple of 10,then what is the value of m+n


a) 784 b) 824 c) 881 d) 924 e) 961

Solve: ||||x – 1| – 2| – 3| – 4|

a. 4 b. 10 c. 14 d. 15
(Please tell me how to approach such multiple Modulus sums)

Ans is C) 881

160000 = 2^4*2^4*5^4
for no to be not a multiple of 10, 2 and 5 should not be together.

so numbers are 2^8 and 5^4
=> 256 + 625 = 881