Number System - Questions & Discussions

how to check?
Why did you accepted 13/2=6.5 and not 23/3 = 7.666 ?
plz edify !

see actually i m testing for authenticity
A/B here both shud be a less than the base system.
for eg. in base system 10 all digits are frm 0 to 9
hence A/B = 2/3 or 4/5 is possible but 11/2 is not ...same thing

How many sets of three or more consecutive odd numbers can be formed such that their sum is 500?

madnikhil Says
How many sets of three or more consecutive odd numbers can be formed such that their sum is 500?


n(2a+d)/2 = 500
Hence n(2a+d) =1000
Hence a= (500/n) -

Now to let n divide 500,n has to be its factors
Therefore 500=2^2 * 5^3
Hence no. of factors = 3*4 =12

But acc. to question,n cannot be 1 or 2.It cannot be 250 or 500
So we are left wid 4,5,10,20,25,50,100,125
Check by inserting it in the above equation.
For n=4, a=125-3=122 (Not possible as number has to be odd)

Checking all,I am getting only one set for n=10,a=41(Not taking into account negative integers,Else Two)
Wats the OA?

Hey puys,Please help me find this!

Find the number of consecutive zeroes at the end of the number (10!+50!+90!+100!)^(15!+25!+50!)

Hey puys,Please help me find this!

Find the number of consecutive zeroes at the end of the number (10!+50!+90!+100!)(15!+25!+50!)


is same as as the power of 5 in 10! 15! = 5
uhhh... Says
is same as as the power of 5 in 10! 15! = 5

Dude,the question is edited...
Please go thru it once again...
Hey puys,Please help me find this!

Find the number of consecutive zeroes at the end of the number (10!+50!+90!+100!)^(15!+25!+50!)

i think the answer shud b 2(15!+25!+50!).....
if its right then i will explain the approach...
dude,the question is edited...
Please go thru it once again...


2(15!+25!+50!)
Hey puys,Please help me find this!

Find the number of consecutive zeroes at the end of the number (10!+50!+90!+100!)^(15!+25!+50!)


Is it 2*(15!+25!+50!) ?

2(15!+25!+50!) is the answer.
Can any of u please explain the approach?

Hey puys,Please help me find this!

Find the number of consecutive zeroes at the end of the number (10!+50!+90!+100!)^(15!+25!+50!)


10! contributes 2 Zeroes In the End....
So, the power above it, would be the leading zeros

So, Answer = 2*(15! + 25! + 50!)
2(15!+25!+50!) is the answer.
Can any of u please explain the approach?

wen we observe the base 10! is the smallest number there....so just take 10! common out of the bracket with the power which is raised to the whole bracket.......

now in the bracket we r left with (1+.....) now in the bracket before adding 1 we will have many zeros in the final term but wen we will add 1 in the end it will spoil all the zeros by adding to the last zero of the number....
so we r left wid the 10! and the same power........
10! will have 2 zeros in the end and theses 2 zeros will get multipied by the power to give the answer.......
i hope it is clear

please help me solve this

What is the remainder when (1! + 2! + 3! + + 100!)^100 is divided by 10?

please help me solve this

What is the remainder when (1! + 2! + 3! + + 100!)^100 is divided by 10?

(1+2+6+24+x0+...)^100 mod 10 =
(x3)^100 mod 10 = 1
remainder = 1
please help me solve this

What is the remainder when (1! + 2! + 3! + + 100!)^100 is divided by 10?

the remainder shud 1.......wats the answer??
please help me solve this

What is the remainder when (1! + 2! + 3! + + 100!)^100 is divided by 10?

ans is 1..
after 5!..we'l start having zeros..so it will be like (1+2+6+24+60+-----X00000000000..24 zeros)^100
after 4,every term will be divisible by 10..as they have zeros..

so add it 1! till 4!=so its 33^100= 3^100=9^50/10 =(10-1)^50/10 =1 remainder

Guys any idea, how to solve problem like this in an efficient way...I am able to solve this by following some pattern
what is the last non zero digit of 1786!

means like in no. 183400, 4 is the last non-zero digit.

hey is the answer 2?

what is the last non zero digit of 1786!

(4^n)*2n! this is the formula for finding the last non-zero..where n=1780/10 in the same ques...

1786!=(4)^178(2*17!*81*82*83*84*85*86
4^178(356!)*

=4^178(4^35)(2*35)!(51*52*53*54*55*56)

4^178(4)^35(70!)(51*52*53*54*55*56)

4^178(4)^350(4)^7(2*7)!(51*52*53*54*55*56)

4^178(4)^35(4)^7(14!)(51*52*53*54*55*56)

4^178(4)^35(4)^7(4)^14(2*14)!(51*52*53*54*55*56)
=6*4*4*6*4((51*52*53*54*55*56)
=6 ans

=6*4*4*6*4*2*4= 6 ans

wow!!
some level solutions...
i had different approach...
still we both got same answer