Question

solve this guys

Answer 1

How have you attempted the problem ??

Answer 2

took N one side and opened the summation term ,,,

Answer 3

Yes, and do you know the kind of series

1/1 + 1/2 + .......1/20 is called ??

Answer 4

I don't what its called bt its like this
N=(1/1 + 1/2 + .......1/20 )fact(20)

Answer 5

1/1 , 1/2, .......1/20 is an example of harmonic progression. Sorry , I have to leave, but check on harmonic progression on google for more info and how to find sum of harmonic progression

Answer 6

It would lead to a big mess nothing else tried solving by it.....

Answer 7

Got the solution but with someone's help

Answer 8

Here the first equation is Stirling number of first kind.

Answer 9

The answer is 10, however my solution is not that efficient.

Answer 10

How do you do it?

Answer 11

i don't know about that but
Here is my friend's soln to it
N=(1/1 + 1/2 + .......1/20 )fact(20)

In this expansion all the terms except fact(20)/11 would give remainder zero
So, Remainder of N is same as when fact(20)/11 is divided by 11
ie rem{fact(10)*1*2*....*9} by 11
remainder of fact(10) by 11 is 10 so Net remainder is rem{10*9*8*.....1}
ie 10 again


Thanx to my friend for wonderful solution

Answer 12

Nice.

Answer 13

Good solution @sahil51993

Answer 14

What is the problem source?

Answer 15

Its from a institute's package in which I'm enrolled

Answer 16

IIT-JEE?

Answer 17

no
CAT

Answer 18

CAT ? Would you mind sharing institute's name privately via message

Answer 19

lol, I am IMS student. I think this is probably from TIME ?

Answer 20

BINGO

Answer 21

Yaa, TIME ofcourse :D

Answer 22

Aha! nice.

Answer 23

Are you two guyz CAT aspirants???

Answer 24

I am enrolled to IMS for 2012, if that's what you are asking :)

Answer 25

I have just passed 12th :D

Answer 26

Good ,,,, that's mean we are competitors for this times CAT exam

Answer 27

@shivam_bhalla did u gave JEE???

Answer 28

like 1 lakh 50 thousand+ others :)

Answer 29

:) much more than that

Answer 30

Yep . I made a blunder in my IITJEE . :(

Answer 31

Because of that, I lost my selection. :(

Answer 32

this year or previous year???

Answer 33

This year

Answer 34

ok guys com back to the actual problem

Answer 35

all we need to do is to find the reminder when 20! is divided by 121
try and find out

Answer 36

its done !!!! read above comments