For which of the following was the mali city of timbuktu best known?
a. its location on the niger river
b. its salt and gold trade
c. its education and wealth
d. its role as a government center

keeping a cash reserve because cash flow is the the movement of money through a company and if it just sits there, it wont the movement

254.34

step-by-step explanation:

the formula for area of a circle is given by

a = pi * r^2

a = pi * 9^2

a = 81*pi

using 3.14 as an approximation for pi

a = 3.14*81

a = 254.34