A stack of $10 bills is worth $90 billion dollars. What is the height of the stack in kilometers? Assume each bill is .2 millimeters high.

1800 kilometers ?

To find the height of the stack in kilometers, we need to go through a series of calculations.

First, let's determine the number of bills in the stack. Since a stack of $10 bills is worth $90 billion dollars, we divide the total value by the value of each bill to find the number of bills:

Number of bills = Total value / Value of each bill

Number of bills = $90,000,000,000 / $10 = 9,000,000,000

Now that we know there are 9,000,000,000 bills in the stack, we can calculate the total height by multiplying the number of bills by the height of each bill:

Total height = Number of bills * Height of each bill

Total height = 9,000,000,000 * 0.2 mm = 1,800,000,000 mm

Since the height is currently in millimeters, we need to convert it to kilometers. To do this, we divide the height in millimeters by 1,000,000 (since there are 1,000,000 millimeters in a kilometer):

Height in kilometers = Total height / 1,000,000

Height in kilometers = 1,800,000,000 mm / 1,000,000 = 1800 km

Therefore, the height of the stack of $10 bills is 1800 kilometers.