How many pennies would you need to stack to make a kilometer if you have 10 pennies in 1.5 centimeter?

You would need 66,666,667 pennies stacked to reach a height of one kilometer, based on your provided measurement of 10 pennies in 1.5 centimeters.

Calculation

Here is the breakdown of the calculation:

Determine the thickness of a single penny based on the provided information:

10 pennies = 1.5 cm

1 penny = 1.5 cm / 10 = 0.15 cm

Convert the target height to the same unit (centimeters):

1 kilometer = 1,000 meters

1 meter = 100 centimeters

1 kilometer = 1,000 * 100 cm = 100,000 cm

Calculate the total number of pennies needed:

Total pennies = Total height / Thickness per penny

Total pennies = 100,000 cm / 0.15 cm per penny

Total pennies = 666,666.67 pennies

Rounding to the nearest whole penny, you would need 666,667 pennies.