Answer:
1) The shoes were purchased at a 40% discount.
2) In order to treat 150 patients, the health department will require 9 vials of the malaria serum.
Step-by-step explanation:
1) If the original cost of the pair of shoes was $40, and you paid $24, then we want to set up a proportion to solve for the discounted percentage.
The discounted percentage is what you DID NOT pay, therefore we will find the amount of money saved first before setting up our proportion
$40 - $24 = $16
Meaning you did not pay that extra $16
Using that deficit, let's set up a proportion in terms of the total:
16/40 = 0.4
To find the percentage that was discounted we must multiply our proportion by 100%
0.4 *100% = 40%
Therefore, the shoes you had bought were on sale for 40% off.
2) If the health department expects 6 vials of malaria serum to treat 100 patients then our proportion of vials to patients becomes
6/100
To solve for how many vials will be required to treat 150 patients, we must equate our expected proportion to one with those 150 patients
6/100 = x/150 Where x denotes the number of vials needed.
Multiply both sides by 150 to isolate x
900/100 = x Reduce the fraction
9 = x
Therefore, in order to treat 150 patients, the health department will require 9 vials of the malaria serum.