M4maths Previous Puzzles

15 Jul 2020 Handshakes

In a party there are 24 persons present. If each of them shakes hand with all the other persons,in total how many handshakes will take place?

OPtion

1) 206
2) 216
3) 226
4) 236
5) 256
6) 266
7) 278
8) 286
9) 276
10) None of these

Solution

Out of 24 persons, the first person will shake hand with 23 persons.
The second person will shake hand with 22 persons (because he has already shaken hand with first person).
The third person will shake hand with 21 persons and so on. The second last person shakes hand with only one person. And last will shake hand with none
(because he has already shaken hand with all persons).
In order to find the total number of handshakes you have to add all the natural numbers from 1 to 23 i.e. ∑ 23.
∑23 = 23 x 24/2 = 276 = 276 handshakes.

Correct Option: 9 Best Solution (1)

G.S.Kantharao   4 years AGO

Sigma 23=276
My option is 9✍️

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