Problem with converting km to miles

[Guest]

I have a story problem for pre-algebra that I am having trouble with;

Keshia traveled at 90km/hr for 3 hours. She needs to travel 200 miles. How much farther shoes she need to travel. Give the answer in miles.

 

[Gene]

i mile is 1.609 km so 270 (90*3) km is 270/1.609 miles.
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Gene

 

[tkhunny]

I NEVER remember how to convert directly from KM to miles.

I do know that:
1 Km = 1000 m
1 m = 100 cm
2.54 cm = 1 in
12 in = 1 ft
5280 ft = 1 mi

You don't have to know a direct route, just so long as you do get where you are going.

 

[math-tutor]

I have a story problem for pre-algebra that I am having trouble with;

Keshia traveled at 90km/hr for 3 hours. She needs to travel 200 miles. How much farther shoes she need to travel. Give the answer in miles.

First convert km traveled to miles.

1 km = 0.6214 mile

270 km x 0.6214 = 167.778 miles.

I am sure you can do the rest.

You can also apply dimensional analysis.

Your conversion factor is 1 mile/1.6093 km

270 km x 1 mile/1.6093 km

The km cancels.

 

[Guest]

another way to do the conversion is to use 1 km = (5/8) mile

or 1 mile = (8/5) km.

This is not quite as accurate as the conversions given above by other people but these are quite acceptble to use- and easier to recall.