We want to determine who received the better discount on a novel. Let's find the sale price of the novel for each person, starting with Mrs. Robinson. We can find the dollar amount of the discount that Mrs. Robinson got using the percent equation.
part = percent * whole
We are given that Mrs. Robinson bought the novel on sale for 20 % off its regular price of $ 29.99. Let r represent the dollar amount of the discount.
r = 20 % * $ 29.99
We need to write the percent as a decimal before we can solve the equation that we created. We can do this by ignoring the percent symbol and moving the decimal point two places to the left.
Therefore, 20 % is equal to 0.20, or 0.2.
r = 20 % * $ 29.99 [0.3em] ⇓ [0.3em]
r = 0.2 * $ 29.99
Now we can solve the equation for r. For simplicity, we will ignore the units for now.
We got that r= 6.00 is a solution to the equation. This means that the book was discounted by about $ 6.00. Now we can calculate the sale price of the novel by subtracting $ 6.00 from the regular price.
$29.99 - $ 6.00 = $ 23.99
Mrs. Robinson bought the novel for $ 23.99. Now let's find the sale price of the novel for Mr. Chang. We know that he bought the novel for 10 % off its regular price of $ 25. Let c represent the dollar amount of the discount.
part = percent * whole
⇓
c = 10 % * $ 25
Like before, we start by rewriting the percent as a decimal by ignoring the percent symbol and moving the decimal point two places to the left.
c = 10 % * $ 25 [0.3em] ⇓ [0.3em]
c = 0.1 * $ 25
Now we can solve the equation for c.
We found that Mr. Chang's book was discounted by $ 2.50. Let's calculate the price of the novel by subtracting the $ 2.50 from the regular price.
$25 - $ 2.50 = $ 22.50
Mr. Chang bought the novel for $ 22.50. Now we can compare the sale prices of the two books.
ccc
Mrs. Robinson& &Mr. Chang [0.4em]
$ 23.99 & > & $ 22.50
Mr. Chang received the better discount because he paid less for the book.
