Have $31.00 and must pay 7% sales tax. If you wish to leave 20% tip on the total bill(meal plus tax) what is the maximum price of lunch can you order?

Answer 1

7% tax of an unknown amount x = .07 x.

Add that to the unknown amount x: x + .07x = 1.07x

To add a 20% tip you multiply .20 times 1.07x = .2014x for the tip

Add the amount and tip: and you get .1.07x + .2014x =1.2714x

This must be less than or equal to $31: 1.2714x = 31.00

x = 31.00/1.2714 = $24.38