D
Radius of the circle is the length of rectangle divided by 2 (7cm)
Area of circle: pi*r²
Pi= 22/7
(22/7)*7²
=154
Since its a half circle, divide 154 by 2 =77
Area of rectangle:14*9=126
Subtract the circle from the rectangle: 126-77=49
8000(.09)=720 8000+720=8720
Answer:
380 different ways
Step-by-step explanation:
We can solve this problem using a permutation formula, as the order in a group of two students matter.
So, for this problem, we have 20 students and want to form groups of 2, so we have a permutation of 20 choose 2:
P(20,2) = 20! / (20-2)! = 20! / 18! = 20 * 19 = 380 different ways
Another way to solve this problem is:
For the first student being chose, we have 20 students available, and for the second student, we have just 19, as one was already chose, so the number of ways to choose these two students is 20 * 19 = 380
Set the bottom equal to 0
x - 8 = 0
x = 8
