Let x = price of the bike before a sales tax.
The price after a sales tax of 8% is
x + 0.08x = 1.08x dollars
Because the price paid was $171.18, therefore
1.08x = 171.18
x = 171.18/1.08 = $158.50
Answer: 158.50
The answer is a no other option
She can buy 3 tubes be cause 8.50 time 2 is less then 20$ but 8.50 times three is more than 20$ its 25.5
Is there another part to your question