Linear Equations II

Hong Kong

Stage 4 - Stage 5

Consider the following phone plans:

GO SMALL plan: This plan has a $\$20$$20 monthly base charge and charges $90$90 cents per minute for all calls.

GO MEDIUM plan: This plan has a $\$26$$26 monthly base charge and then charges $70$70 cents per minute for all calls.

a

Complete the following table of values for various total monthly call times for the two plans:

Call time (in minutes) | Total cost for GO SMALL plan | Total cost for GO MEDIUM plan |
---|---|---|

$20$20 | $\editable{}$ | $\editable{}$ |

$30$30 | $\editable{}$ | $\editable{}$ |

$40$40 | $\editable{}$ | $\editable{}$ |

$50$50 | $\editable{}$ | $\editable{}$ |

b

Sketch the graph of the two plans.

Loading Graph...

c

Using the graphs, determine how many minutes of calls would need to be made so that the monthly bill costs the same on both plans.

Easy

Approx 7 minutes

The cost of manufacturing toys ($C$`C`) is related to the number of toys produced ($n$`n`) by the formula $C=400+2n$`C`=400+2`n`. The revenue ($R$`R`) made from selling $n$`n` toys is $R=4n$`R`=4`n`.

The cost for a furniture manufacturer to make a dining table is $\$450$$450 per dining table plus a fixed setup cost of $\$6000$$6000. The dining tables will sell for $\$700$$700 each.

This graph shows the cost $C\left(x\right)$`C`(`x`), the revenue $R\left(x\right)$`R`(`x`) and the profit $P\left(x\right)$`P`(`x`) from making and selling $x$`x` units of a certain good.

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