A family trip to a zoo cost $175.54. They paid using a credit card that carries a 12% simple interest rate. If the bill was paid off in 3 months. How much did they pay?

The simple interest formula is I= P•r•t

P is the principle amount $175.54
r is the interest rate, 12% (the decimal would be 0.12)
t is the time involved, 3 months, by 12, since there 12 months in a year
T would be .25 year time period

So if you plug everything in the equation would be 175.54•0.12•0.25

Making the interest $5.27
Then you add that to the original amount making the answer $180.81

I hope It helps!