The quotient of a circle's circumference and diameter gives an approximate value of

a. area
b. diameter
c. radius
d. circumference
e. pi

E. Pi 

If you measure the distance around a circle and divide it by the distance across the circle through its center, you will always come close to a particular value, depending upon the accuracy of your measurement. This value is approximately 3.14159265358979323846... We use the Greek letter (Pi) to represent this value. Using computers, mathematicians have been able to calculate the value of to billions of places.

20y5 times 2 is 1010 times -2 is -20, plus y

Definitely