# ACT Aspire Math: How Many Pennies Are in Doug's Jar?

A single penny has a volume of 0.36 cubic centimeters. Douglas has a cylindrical jar that is 20 centimeters high and has a radius of 4 centimeters.

If Douglas's jar is completely filled with pennies, approximately how many pennies does Douglas have? Use V = πr2h for the volume of a cylinder.

ACT Aspire | Math |

ACT Aspire Math | Measurement |

Math | Measurement |

Product Type | ACT Aspire |

Test Prep | ACT Aspire ACT Aspire Math |

### Transcript

with pennies approximately how many pennies does douglas have And

we're going to use the formula here The volume equals

pi r squared height for the volume of cylinder Okay

so doug's been procrastinating about going to the coin star

kiosk and now his chilean jar of pennies Well time

to trade those little copper abe lincoln's for some george

washington's or maybe even a ben franklin do well the

first step here is to calculate the volume of the

jar A cylinder with height h and radius r has

a volume of pi r squared h So we just

plop in the measurements of douglas jar that gets us

v equals pi times four squared times twenty which is

pi times sixteen times funny or three twenty pike cubic

centimeters Well we need the number for our next step

in decimal form So it's time to bust out our

handy dandy calculator and i'll take three point one four

as pie and that gets us And what is that

About a thousand and five cubic centimetre or something like

that Well the number of pennies that fit in the

jar can be approximated by dividing the volume of the

jar by the volume of one penny So that gets

us a was that about a thousand voted by point

three six gets us in twenty eight hundred so douglas

can't have half a penny is that we're going around

the number there too The exact Numbers of 2790 three

pennies So that's the number It's a twenty seven dollars

ninety three cents and that's just awesome Just in time

to pay for another month of his you know shmoop 00:01:36.832 --> [endTime] subscription plan Thank you very much We'll take that