1.Colin walked a distance of 15 miles in 6 hours. Work out Colins average speed.
Give your answer in miles per hour.

2.Tim drives at an average speed of 80km per hour for 3 hours 45 minutes.
Work out how many kilometres Tim drives.

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The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?