How do you know a number is divisible by 10?

There is a spinner with 14 equal areas, numbered 1 through 14. if the spinner is spun one time, what is the probability that the result is a multiple of 2 or a multiple of 5?

In the diagram, ab is tangent to c, ab = 4 inches, and ad = 2 inches. find the radius of the circle.

The width of a rectangle is half as long as the length. the rectangle has an area of 18 square feet. what are the length and width of the rectangle?