Answer:
ok.
1. Tanya spends exactly $30.
She can spend $15.00 each for 2 t shirts and spend $30.00
15 x 2 = 30
She can buy one $15.00 t shirt, one $10.00 t shirt and one $5.00 t shirt for exactly $30.00.
15 + 10 + 5 = 30
She can buy one $15.00 t shirt, and three $5.00 t shirts for exactly $30.00
15 + 5 + 5 +5 = 30
2. To spend exactly $25.00, Tanya can spend it :
5 of the $5.00 t shirts
5 x 5 = 25
2 of the $10 t shirts and one of the $5 t shirts
10 + 10 + 5 = 25
1 of the $15 t shirts and one of the $10 t shirts
15 + 10 = 25
1 of the $15 t shirts and 2 of the $5 t shirts
15 + 5 + 5 = 25