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!
<span>If the nemesis has "7/8 of her cats plus 2" it can be written like this: 7/8 x + 2 = x, where x is the number of the cats. After that we can solve the equation. x - 7/8 x = 2; 1/8 x = 2; x = 2 : 1/8 = 2 * 8 = 16. Answer: The nemesis has 16 cats.</span>
Answer:
v = 0.416 m/s
Step-by-step explanation:
Give that,
Distance covered by a train, d = 50 m
Time taken, t = 120 s
We need to find the speed of a train. The formula for speed of an object is equal to the total distance covered divided by total time taken. It can be given by :
So, the speed of a train is 0.416 m/s.
Step-by-step explanation:
The center of a circle with 2 end points of a di diameter is the midpoint of the two endpoints.
The formula needed to find the minpoints is
(x,y) = (x2 + x1)/2, (y2 + y1)/2
x2 = 3
x1 = 3
y2 = 0
y1 = -7
midpoint = (3 + 3)/2, (0 - 7)/2
midp[oint = 3,-3.5
The midpoint is the center of the circle. Observe that the signs get changed when entering the values for (x,y)
So far what you have is (x - 3)^2 + (y + 3.5)^2 = r^2
To determine r^2 you need only take the distance from the center to oneof the endpoints.
r^2 = (3 - 3)^2 + (3.5 - 0)^2
r^2 = 3.5^2
r^2 = 12.25
Answer: (x - 3)^2 + (y + 3.5)^2 = 12.25
Answer:
C and E I think
Step-by-step explanation:
They both represent taking number of people, or population
