Verbal Reasoning - Arithmetic Reasoning - Discussion
Discussion Forum : Arithmetic Reasoning - Section 2 (Q.No. 19)
19.
At the end of a business conference the ten people present all shake hands with each other once. How many handshakes will there be altogether ?
Answer: Option
Explanation:
Clearly, total number of handshakes = (9+ 8 + 7 + 6 + 5 + 4 + 3 + 2+1) = 45.
Discussion:
8 comments Page 1 of 1.
Arin said:
4 years ago
Their is an equation going around -> n (n-1) /2.
Can anyone please explain me why there is a "/2" in that equation?
Can anyone please explain me why there is a "/2" in that equation?
Veeresh said:
5 years ago
n(n-1)/2.
n = no of persons.
n = no of persons.
(1)
Shivam said:
7 years ago
There is a shortcut to solving this problem.
n*(n-1)/2.
Here n=10.
So, answer will be 10 * 9/2.
= 90/2.
= 45.
n*(n-1)/2.
Here n=10.
So, answer will be 10 * 9/2.
= 90/2.
= 45.
RuAn said:
7 years ago
You are right, @Manish.
Manish Kumar said:
8 years ago
It's (n!)/(n-r)!*r!.
No of people = 10.
Each hand shakes = 2.
So 10!/8!*2!= 45.
No of people = 10.
Each hand shakes = 2.
So 10!/8!*2!= 45.
(1)
Parul Garg said:
8 years ago
Nice @Mukun.
Mahii said:
8 years ago
The last person will not shake hand with anybody. So 1 should be taken out from calculation and answer should be 44.
Mukun said:
9 years ago
n(n_1)\2.
=> 10 * 9/2,
=> 90/2,
=> 45.
=> 10 * 9/2,
=> 90/2,
=> 45.
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