Question

Question #b881e

Answer 1

13 miles is equal to 20.9 km.

Explanation:

Please refer to the following link where I explain, and demonstrate, my method of multiplying by 1 for a similar problem.
https://socratic.org/questions/a-mile-is-5280-ft-long-1-ft-is-approximately-0-305-m-how-many-meters-are-there-i#469538

Using the multiply by 1 method:
`"13 miles" * "5280 feet"/"1 mile" * "12 inches"/"1 foot" * (2.54 cm)/"1 inch" * "1 m"/"100 cm" * * "1 km"/"1000 m" = "the answer"`
Next, notice as the units of the intermediate conversions cancel out.
`13 cancel("miles") * (5280 cancel("feet"))/(1 cancel("mile")) * (12 cancel("inches"))/(1 cancel("foot")) * (2.54 cancel(cm))/(1 cancel("inch")) * (1 cancel(m))/(100 cancel("cm")) * "1 km"/(1000 cancel("m")) = 20.9 "km"`

I hope this helps,
Steve