In this case we can propose a rule of three:
$ 18 ---------------> 100%
x --------------------> 25%
Where x represents the discount made to the pillow:
[tex]x = \frac {25 * 18} {100}\\x = 0.25 * 18\\x = 4.5[/tex]
So we have the new price (with the discount) is:
[tex]P = 18- (0.25 * 18)\\P = 18-4.5\\P = 13.5[/tex]
In addition, if 25% is discounted we have to, the price of the pillow is 75% of the original price. That is to say:
[tex]0.75 * 18 = 13.5[/tex]
Answer:
Option A
[tex]P = 18- (0.25 * 18)[/tex]
Option D
[tex]P=0.75*18[/tex]
