= 16 + 15 - (15 - 18)^2
= 31 - (-3(^2
= 31 - 9
= 22
answer
B. 22
So the numbers on the credit card can start with any single-digit number
So it could start with;
0
1
2
3
4
5
6
7
8
Or 9
We are looking for the odds of it starting with a 7
There is only one 7, so the numerator is 1
There are then nine other possible numbers it could be, and counting the number 7, there is a total of ten different possibilities, so 10 is the denominator
So the odds of the card starting with a 7 is
1/10
Answer:
Correct choice is D
Step-by-step explanation:
Consider regular 60 sided polygon (regular means all sides are of equal length). Connect the center of this polygon with each polygon's vertex. You get 60 equal isosceles triangles with base that is polygon's side. The measure of the angle opposite to the base is
![\dfrac{360^{\circ}}{60}=6^{\circ}.](https://tex.z-dn.net/?f=%5Cdfrac%7B360%5E%7B%5Ccirc%7D%7D%7B60%7D%3D6%5E%7B%5Ccirc%7D.)
Rotating the polygon by 6° over the center, each such triangle will map onto the previous triangle. Thus, the least angle by which a regular 60-gon can be rotated so that it maps onto itself is 6°.
Because both angles are 90° and 90+90=180