There would be 12 people at the party!
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.
Hope this helps!
Answer:
0.01
Step-by-step explanation:
0.1 x 0.1 = 0.01
HOPE IT HELPS YOU
Answer:
Associative.
Step-by-step explanation:
In addition and multiplication, it does not matter which two numbers you put together first. On the left aide 6 is associated with 3. On the right side 3 is grouped with 7. It doesn't matter where 3 goes. You still get the same answer.
(6 + 3) + 7 = 6 + (3 + 7)
9 + 7 = 6 + 10
16 = 16
Answer:
$82.5
Step-by-step explanation:
$16.50 * 5 = $82.5
The mean is the average.
Add all the number of pets and divide by how many people there were.
3+5+2+4+1
15/number of people
15/5
=3
Hope this helps :)
