Brain bought 2 shirts for 14.50 each and a pair of shoes for 29.99 the sales tax was 6%

Cost of each shirt bought by Brain = 14.50
Then
Cost of 2 shirts bought by Brain = 2 * 14.50
                                                    = 29
Cost of a pair of shoes = 29.99
Total amount spent by Brain before tax = 29 + 29.99
                                                               = 58.99
Percentage of sales tax that needs to be paid = 6%
Amount of sales tax that needs to be [paid = (6/100) * 58.99
                                                                     = 353.94/100
                                                                     = 3.54
So
the total amount spent by Brain including tax = 58.99 + 3.54
                                                                         = 62.53
I hope this is the answer you were looking for.

If i'm correct the answer is $15.97