old price $18
new price $18 20%
0 3.6 18 21.6 The top is dollars and the bottom is percentage.
0% 20% 100% 120%
What is the same?
What is different
Why is the answer equal to 120%
Examine this proportion 120 over 100= x over 18
What does 18 divided by 100=0.18 tell you?
why do you multiply 0.18 by 120?
The same:
- The price of the item is still $18.
Different:
- The discount amount changed from 0% to 20%.
Why is the answer equal to 120%?
- The answer is equal to 120% because when you apply a 20% discount to the original price of $18, you are left with 80% of the original price. To find the new price, you add the 80% (which can be written as 80/100 or 0.8) to the original price of $18. Mathematically, the new price can be calculated as 18 + (0.8 * 18) = 18 + 14.4 = $32.4. Therefore, the new price is $32.4, which is a 120% increase from $18.
Examining the proportion 120 over 100= x over 18:
- This proportion is used to calculate the new price, where x represents the unknown new price. By cross-multiplying the proportion, you get (120 * 18) = (100 * x). Simplifying this equation gives you 2160 = 100x, and dividing both sides by 100 results in x = 21.6. Hence, the new price is $21.6.
What does 18 divided by 100 = 0.18 tell you?
- By dividing 18 by 100, you get 0.18, which represents 18% of the original price. This means that if you apply a 100% discount to the original price, the new price would be $0.18.
Why do you multiply 0.18 by 120?
- The number 0.18 is multiplied by 120 to find the 20% discount amount. Multiplying 0.18 by 120 gives you 21.6, which represents the amount that is subtracted from the original price of $18. Therefore, the new price can be calculated as 18 - 21.6 = $-3.6. Note that a negative value indicates a discount or reduction in price. However, it is not possible for the new price to be negative in this example, so the correct discount amount is actually $21.6.