Sale! & Tax :(
When there is a sale, we _______. When there is a tax or a tip, we _______.
When there is a sale, we subtract. When there is a tax or a tip, we add.
If we don't know the original price, what should we use in its place?
a. a constant
b. a coefficent
c. a variable
d. any number we choose!
A variable!
A trampoline was originally priced at $100 but went on sale for 60% off. If Ellias bought the trampoline and paid 5% sales tax, how much did he pay in total?
0.6 x 100 = 60
100 - 60 = $40 sale price.
0.05 x $40 = $2.
$40 + $2 = 42
A desk costs $500 and is on sale for $60% off. What is the sale price?
0.6 * 500 = 300.
500 - 300 = 200 dollars
A bicycle is on sale for 75% off. If you have to pay $117, what was the original price?
b - 0.75b = 117
0.25b = 117
117 / 0.25 = $468
The bicycle originally cost $468.
Justin bought a basketball originally priced at $40 but on sale for 50% off. After 10% sales tax, what was the total cost?
40 - 20 = $20
0.1 * 20 = $2
$20 + $2 = $22
A stapler costs $15. But when you get to the register, they tell you there is a 12% sales tax. How much do you have to pay for the stapler, including the sales tax?
15 + 1.8 = $16.80
After paying a 20% tip, the Sosa family pays $60 for a meal at a restaurant. What was the price, before the tip?
m + 0.2m = 60
1.2m = 60
60 / 1.2 = 50
The meal cost $50 before the tip.
Joel went shopping for a guitar in Fairfax. He purchased one originally priced at $240 but discounted 80%. If sales tax in Fairfax is 9.25%, what was the total cost?
240 - (0.80 x 240) = $48
48 x 0.0925 = $4.44
48 + 4.44 = $52.44
A hamburger and fries cost $8.50. If you also have to pay a 18% tip, how much do you pay in total for the burger and fries?
8.50 x 0.18 = 1.53
8.50 + 1.53 = $10.03
A camera is on sale for 30% off. The sale price is $322. What was the original price of the camera?
c - 0.3c = 322
0.7c = 322
322 / 0.7 = 460
The camera cost $460 before the sale!
Jada has a coupon code for Uber Eats, so she gets 30% off of her meal. She decides to add a 15% tip on the original price of her meal. If the meal originally cost $30, how much does Jada have to pay, including the tip?
30 - (0.3 x 30) = $21
21 + (0.15 x 30) = $4.50
$21 + $4.50 = $25.50
A pair of boots cost $80. Marvin uses a $25 coupon and Isaiah uses a 25% coupon. Who spends more? What is the difference in cost between what Marvin pays and what Isaiah pays?
Marvin: 80 - 25 = $55
Isaiah: 0.25*80 = 20 ... 80 - 20 = $60.
Isaiah pays $5 more than Marvin.
A giant box of pencils cost $c on amazon. Mr. Lefkowitz has to pay a 12% tax, on the $c cost. He also needs to pay a 15% delivery fee, on the $c cost. After the tax and the fee, Mr. Lefkowitz has to pay $19.05. What was the original price of the box of pencils?
Tax: 0.12 x c = 0.12c
Delivery Fee: 0.15 x c = 0.15c
1c + 0.12c + 0.15c = $19.05
1.27c = 19.05
A new school bag costs originally costs $25 on Amazon. There is a sale for 60% off. But then you have to pay $5 delivery fee and a 12% tax on the sale price. How much do you have to pay in total for the school bag?
25 - (0.6 x 25) = $10.
+ Tax: (0.12 x 10) + 10 = $11.20
+ Delivery Fee: 11.20 + 5 = $16.20