The sales tax on a 15,000 car is 540. at this rate what is the tax on a 32,000 car

Note : Since unit of currency is not defined, I'll be using units.

Sales tax on a 15000 units car = 540 units
540 = 15000 × tax% / 100
=> 540 = 15000 × tax% / 100
=> 540/15000 = tax% / 100
=> tax% = (540/15000) × 100
=> tax% = 540/140
=> tax% = 3.6

now,
sales tax on a 32000 units car = 32000 × tax%/100
= 32000 × 3.6/100
= 320 × 3.6
= 1152 units
therefore sales tax on a 32000 units car = 1152 units

What is your question again i don't understand