#21
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Quote:
let see if 10 people ...then 1st person = 9 handshake 2nd person = 8 handshake (coz handshake with 1st person already counted) 3rd person= 7 handshake ( coz handshake with 1st and 2nd person already counted above) and so on .... it is sumthing like : 9+8+7+6+5+4+3+2+1 =45 :P but for large number u cant do this .. so just remember this formula for this type of question n*n-1 = r then r/2= Answer now apply on above question 10*9=90 then 90/2 = 45 |
#22
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10*9=90 90/2= 45
10 people will shake hand with 9 people in 90 times but with repetition (aslam shakes hand with aslam and aslam shakes hand with akram) thats why we devided 90 by 2 so we get 45
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