Grade 8 Algebra: Word Problems: Functions

Name: ______________________Date: ____________Score: ____ / 8

Level 3

Build the function

1. Solve:
$\text{A}$ $\text{gym}$ $\text{charges}$ $\text{a}$ $\text{40}$ $\text{dollar}$ $\text{joining}$ $\text{fee}$ $\text{plus}$ $\text{25}$ $\text{dollars}$ $\text{per}$ $\text{month.}$ $\text{Write}$ $\text{a}$ $\text{function}$ $\text{for}$ $m\text{}$ $\text{months}$ $\text{and}$ $\text{find}$ $\text{the}$ $\text{cost}$ $\text{for}$ $\text{1}$ $\text{year.}$
2. Solve:
$\text{A}$ $\text{tank}$ $\text{holds}$ $\text{90}$ $\text{liters}$ $\text{and}$ $\text{drains}$ $\text{6}$ $\text{liters}$ $\text{per}$ $\text{minute.}$ $\text{Write}$ $\text{a}$ $\text{function}$ $\text{for}$ $t\text{}$ $\text{minutes}$ $\text{and}$ $\text{find}$ $\text{when}$ $\text{it}$ $\text{is}$ $\text{empty.}$
3. Solve:
$\text{A}$ $\text{4}$ $\text{mile}$ $\text{taxi}$ $\text{ride}$ $\text{costs}$ $\text{11}$ $\text{dollars}$ $\text{and}$ $\text{a}$ $\text{10}$ $\text{mile}$ $\text{ride}$ $\text{costs}$ $\text{23}$ $\text{dollars.}$ $\text{Write}$ $\text{a}$ $\text{linear}$ $\text{function}$ $\text{for}$ $\text{the}$ $\text{cost}$ $\text{of}$ $m\text{}$ $\text{miles.}$
4. Solve:
$\text{A}$ $\text{plant}$ $\text{is}$ $\text{8}$ $\text{cm}$ $\text{tall}$ $\text{after}$ $\text{2}$ $\text{weeks}$ $\text{and}$ $\text{14}$ $\text{cm}$ $\text{tall}$ $\text{after}$ $\text{5}$ $\text{weeks.}$ $\text{Write}$ $\text{a}$ $\text{function}$ $\text{for}$ $w\text{}$ $\text{weeks}$ $\text{and}$ $\text{find}$ $\text{its}$ $\text{height}$ $\text{at}$ $\text{planting.}$
5. Solve:
$\text{Plan}$ $\text{A}$ $\text{costs}$ $\text{30}$ $\text{dollars}$ $\text{plus}$ $\text{5}$ $\text{dollars}$ $\text{per}$ $\text{class.}$ $\text{Plan}$ $B\text{}$ $\text{costs}$ $\text{10}$ $\text{dollars}$ $\text{per}$ $\text{class.}$ $\text{For}$ $\text{how}$ $\text{many}$ $\text{classes}$ $\text{do}$ $\text{they}$ $\text{cost}$ $\text{the}$ $\text{same?}$
6. Solve:
$\text{A}$ $\text{car}$ $\text{has}$ $\text{50}$ $\text{liters}$ $\text{of}$ $\text{fuel}$ $\text{and}$ $\text{uses}$ $\text{4}$ $\text{liters}$ $\text{every}$ $\text{50}$ $\text{km.}$ $\text{How}$ $\text{much}$ $\text{fuel}$ $\text{is}$ $\text{left}$ $\text{after}$ $\text{300}$ $\text{km?}$
7. Solve:
$\text{An}$ $\text{empty}$ $\text{bucket}$ $\text{weighs}$ $\text{2}$ $\text{kg}$ $\text{and}$ $\text{each}$ $\text{liter}$ $\text{of}$ $\text{water}$ $\text{adds}$ $\text{1}$ $\text{kg.}$ $\text{Write}$ $\text{a}$ $\text{function}$ $\text{for}$ $x\text{}$ $\text{liters}$ $\text{and}$ $\text{find}$ $\text{the}$ $\text{weight}$ $\text{with}$ $\text{7}$ $\text{liters.}$
8. Solve:
$\text{A}$ $\text{printer}$ $\text{warms}$ $\text{up}$ $\text{for}$ $\text{1}$ $\text{minute,}$ $\text{then}$ $\text{prints}$ $\text{18}$ $\text{pages}$ $\text{per}$ $\text{minute.}$ $\text{How}$ $\text{many}$ $\text{pages}$ $\text{are}$ $\text{printed}$ $\text{in}$ $\text{6}$ $\text{minutes?}$