Regina paid a total of $32.40 for two shirts, including 8% sales tax. One of the shirts cost $17.50 before tax

Question

Regina paid a total of $32.40 for two shirts, including 8% sales tax. One of the shirts cost $17.50 before tax. How much did the other shirt cost?

GPT-5 mini · Answer

Let the pre-tax total be S. Then S(1 + 0.08) = 32.40, so S = 32.40 / 1.08 = 30.00.  
The other shirt cost 30.00 − 17.50 = $12.50.

Regina paid a total of $32.40 for two shirts, including 8% sales tax. One of the shirts cost $17.50 before tax. How much did the other shirt cost?