Question 1.9: An individual donated 1.0 pint of blood at the local blood b...

[1] Identify the original quantity and the desired quantity.

1.0 pt                                       ? L
original quantity                 desired quantity

[2] Write out the conversion factors.

• We have no conversion factor that relates pints to liters directly. We do, however, know conversions for pints to quarts, and quarts to liters.

[3] Solve the problem.

• To set up the problem so that unwanted units cancel, arrange each term so that the units in the numerator of one term cancel the units of the denominator of the adjacent term. In this problem we need to cancel both pints and quarts to get liters.
• The single desired unit, liters, must be in the numerator of one term.

[4] Check.

• Since there are two pints in a quart and a quart is about the same size as a liter, one pint should be about half a liter. The answer, 0.47, is just about 0.5.
• Write the answer with two significant figures since one term, 1.0 pt, has two significant figures.