How do I do interest rate word problems?

Investment problems usually involve simple annual interest (as opposed to compounded interest), using the interest formula I = Prt, where I stands for the interest on the original investment, P stands for the amount of the original investment (called the "principal"), r is the interest rate (expressed in decimal form), and t is the time.

Step-by-step explanation: -hope this helps

equation is

interest= interest rate x principal  

Key: interest is the amount that is unknown

interest rate is the percent

Principal is the original amount started with.

Step-by-step explanation:

$18 was the price of the t-shirt

step-by-step explanation:

x=6 and x=3

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