An item costs $330 before tax, and the sales tax is $16.50 . find the sales tax rate. write your answer as a percentage.

Write the sales tax rate as proper fraction
tax rate = 16.5/330

simplify the proper fraction, divide the numerator and denominator by 16.5
tax rate = 16.5/330
tax rate = 1/20

Change the proper fraction into percentage
Percentage means per hundred. We only have to change the denominator into 100 by multiplying the denominator by 5. If the denominator is multiplied by 5, so is the numerator
tax rate = 1/20
tax rate = (1 × 5) / (20 × 5)
tax rate = 5/100
tax rate = 5%

The sales tax rate is 5%