The document contains three math word problems involving expressions of quantities as functions of time. The first problem asks the reader to write an expression showing the gallons of water in a pool being filled at a rate of 50 gallons per minute as a function of time, starting at 400 gallons. The second problem asks for a similar expression showing the gallons in an Olympic size pool being emptied at 60 gallons per minute. The third problem asks the reader to write expressions and graph the pay as a function of time for two apple pickers, one earning $20/hour and one earning $10/hour plus a $50 bonus, and to analyze when their pay was equal.

1. 1) A pool already has 400 gallons in it. It is
being filled at a rate of 50 gallons per minute.
Write an expression that gives the gallons of
water in the pool as a function of time.
2) An Olympic size pool holds a half a
million gallons. It is being emptied at a rate
of 60 gallons per minute. Write an expression
that gives the gallons of water in the pool as a
function of time.
3a) A fast apple picker gets $20/hour. Write
an expression of her pay as a function of
time. Graph the equation. Label the graph.
3b) A new apple picker earns $10/hour. He
receives $50 extra the first day for being a
new hire. Write an expression of his pay as a
function of time. Graph the equation on the
same graph as #3a.
3c) Analyze the graph in words. Determine
when the apple pickers earned the same
amount. Describe before they earn the same
and after they make the same.