Jeremy worked for 8 1/2 hours building model airplanes. If each airplane takes him 1 2/5 hours to make, how many models did he build?
First convert the work time to a mixed number: 8 1/2 hours = 8 hours + 1/2 hour = <<8+1/2=8.5>>8.5 hours
Then divide the total work time by the time it takes to build one model to find the number of models built: 8.5 hours / (1 2/5 hours/model) = 8.5 hours * 5/7 hours/model = 5 models. Answer: \boxed{5}.
into a fraction
To convert 8 1/2 to a fraction, we can multiply the whole number by the denominator and add the numerator.
8 1/2 = (8 * 2) + 1 / 2 = 16 + 1 / 2
16/2 + 1/2 = 17/2
Therefore, 8 1/2 = 17/2.