You can put this solution on YOUR website! I a plane travels 70 miles in 20 minutes. What is the air speed?
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To find miles per minute, divide the miles by the minutes.
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Many factors are not mentioned. Was is 70 miles over the ground? If so, the wind speed and direction have to be considered.
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If it covered 70 miles over the ground in 20 minutes, its GROUNDSPEED was 70/20 miles/minute. No way to know the airspeed.
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People who don't know what they're talking about should not attempt to write math problems. Or anything else.