# Ratios & Percentages

### Topics

## Introduction to :

You will use percents for the rest of your life. That's a promise, not a threat.

Check out the examples for just a few places where percents will cross your path: commission, discounts, sales tax, bank accounts, and tips at restaurants.

#### Commission Example

You landed a fabulous summer job working as a sales assistant at Shmacy's. You earn a 4% commission on every sale you make, in addition to your wage of $8.50/hour. After a long seven-hour shift, your sales totaled $1250. What are your total earnings for that shift? |

#### Discount Example

The Sports Shmauthority is having an amazing sale on all of their winter gear, 65% off the regular price. You find the snowboarding jacket that you have been wanting for the past year. It was $220 before the sale. How much is it now? |

#### Discount Upon Discount Example

All sweaters are 30% off of the original price. You, being the clever shopper you are, also have a coupon for 15% off any item, including sale items. How much does a $75 sweater cost? |

#### Sales Tax Example

Sales tax in the state of California is 9.25%. After shopping at a Shmarget in Laguna Beach, your purchases came to $62.75, before tax. How much do you end up paying, including tax? |

#### Discount and Sales Tax Example

Sweet! Jeans at American Shmeagle are 40% off. How much will you pay for a pair of jeans that were originally $80? (don't forget the 9.25% sales tax)
adding in the sales tax |

#### Compound Interest Example

You invest $200 in a savings account that earns 4% interest |

#### Tips at a Restaurant Example

After a particularly nice lunch, your bill comes to $44.75. You and your two friends split the bill equally. How much do you each owe? (Don't forget to add in a 20% tip!) |

#### Commission Exercise

A used car salesman earns 10% of all sales. After selling an old Shmoyota for $3200, how much money does he earn?

#### Discount Exercise

You have a coupon for 30% off all purchases at The Shmapple Store. Your subtotal comes to $295. How much is total after the discount?

#### Discount Upon Discount Exercise

Shmabercrombie & Finch is having a jeans sale. All jeans are 25% off. You have a coupon for an additional 20% off any item. How much would you pay for a pair of jeans that are originally $85?

#### Sales Tax Exercise

North Dakota sales tax is approximately 5%. Your purchases at a Shmarnes & Noble bookstore total $62. How much do you owe, including sales tax?

#### Discount and Sales Tax Exercise

You need to buy a new pair of sneakers. You have $75. The pair you want are $110, but are 40% off. Do you have enough money if you include an 8.5% sales tax?

#### Simple Interest Exercise

If you invest $500 in a savings account that earns 5% interest each year, how much money will be in the account after 2 years?

#### Tips at a Restaurant Exercise

If your dinner bill totals $38, how much is the total after leaving a 15% tip?