$75 billion in $1 bills and stack them up, how many miles tall would this stack be?

Thank's for help. ::)

Assuming that the width of a bill is 1 mm, and that you are stacking them on top of each other, the height of the stack would be 75 billion mm or 75 million m. This must be changed to km and this is done because 1000m = 1 km so a conversion factor is used. 75,000,000m * 1 km/1000m = 75,000 km. The m cancel out, and the km stay. Then you use the conversion factor for km and miles which is 1 km = .621 miles so, 75,000km * .621 miles/ 1 km = 46575 miles. I hope this answers your question.