Question

a $20 cell phone case is sold in bulk to your store for $16. calculate the trade discount rate.

Explanation:

Step1: Calculate the discount amount

The discount amount is the original price minus the bulk - price. Let the original price \(P = 20\) and the bulk - price \(B=16\). Then the discount amount \(D=P - B\).
\(D = 20-16=4\)

Step2: Calculate the trade - discount rate

The trade - discount rate \(r\) is calculated using the formula \(r=\frac{D}{P}\times100\%\) (where \(D\) is the discount amount and \(P\) is the original price).
Substitute \(D = 4\) and \(P = 20\) into the formula:
\(r=\frac{4}{20}\times100\%=0.2\times100\% = 20\%\)

Answer:

\(20\%\)