• Placement Papers
• /
• Elitmus
• /
• Numerical Ability
• /
• Number System

Elitmus Question Papers:

(#M40030780) ELITMUS Numerical Ability question Keep an EYE

if n is a natural no,
101+102+....n what is the probability that this sum is divisible bu (n-100)?

Asked In Elitmus HEMANTH NAIDU S (10 years ago)

Unsolved Read Solution (11)

Is this Puzzle helpful?   (2)   (1) Submit Your Solution Number System

Read Solution (11) :

Pallavi Chand  (10 years ago)

probability =50%
coz..101/1, 306/3, 515/5, 728/7, 945/9..n so on
so odd nos are divisible...while even nos are not divisible giving odd sum

Is this solution Helpfull? Yes (24) | No (2)  

N Arun Singh  (10 years ago)

1/2
since take add terms like 101(div by 1(101-100)),3rd term(upto 103(306/3).....
even terms (101+102) not div by 2 ..so sum is div wen it is odd ..and not div n is even

Is this solution Helpfull? Yes (4) | No (3)  

sasmita sahoo  (10 years ago)

Ans is 50%
cz 101/(101-100)=101, (101+102)/(102-100)=203/2, (101+102+103)/(103-100)=102, (101+102+103+104)/(104-100)=410/4..
from the abve it clear tht odd nos r divisible and even nos r nt divisible.. so result 50%.

Is this solution Helpfull? Yes (2) | No   

praveen  (10 years ago)

visit this for solution http://www.onlineadhyayana.com/ elitmus section...:)

Is this solution Helpfull? Yes (1) | No (2)  

Rajeswari  (10 years ago)

hi pallavi, how u done d division for 101/1,306/3,525/5,728/7....these numbers? 101,306,515,728...wat are these numbers.cann u xplain me in detail

Is this solution Helpfull? Yes (1) | No (1)  

HEMANTH NAIDU S  (10 years ago)

and in ques they also given (n>100)

Is this solution Helpfull? Yes | No   

N Arun Singh  (10 years ago)

i hav given the explanation but it onli some part is visible ...
@praveen is ma ans corret?

Is this solution Helpfull? Yes | No   

N Arun Singh  (10 years ago)

i hav given the explanation but it onli some part is visible ...
@praveen is ma ans correct?

Is this solution Helpfull? Yes | No   

vivek tiwari  (10 years ago)

sum of this series would be (n^2+n-10100)/2
clearly it is divisible by (n-100)
hence probability must be 1

Is this solution Helpfull? Yes | No   

Harshil Bhatnagar  (10 years ago)

jjljk hh jl

Is this solution Helpfull? Yes | No   

divya  (8 years ago)

probability = 1/2
number of terms : n-101+1=n-100
Sum of numbers using AP formula : (n-100)*(n+101)/2
Sum will be divisible by (n-100) only when (n+101) is divisible by 2
This is possible only when n is odd. [ coz odd number added with odd number gives even number]
Probability of n being odd = 1/2 [Since, only two possibilities are there, n is even or n is odd]

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.