Friends til the end Community Group
A group for those of us here who get more from our friendships than from the available discussion groups. A place to be accepted and appreciated for who we are. Somewhere to always feel safe and know that especially on the bad days we are here for each other .A place for encouragement and love.
At A Party, everyone shook hands with everybody else.
There were 66 handshakes.
How many people were at the Party ?
There were 66 handshakes.
How many people were at the Party ?
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" Name A Term Used In Football " ?
In general, with n+1 people, the number of handshakes is the sum of the first n consecutive numbers: 1+2+3+ ... + n.
Since this sum is n(n+1)/2, we need to solve the equation n(n+1)/2 = 66.
This is the quadratic equation n2+ n -132 = 0. Solving for n, we obtain 11 as the answer and deduce that there were 12 people at the party.
Since 66 is a relatively small number, you can also solve this problem with a hand calculator. Add 1 + 2 = + 3 = +... etc. until the total is 66. The last number that you entered (11) is n.