Question

Mrs. Kosko left $19.47 on the table in a restaurant after receiving the bill for $16.50. If there was no tax, what percent did she tip? (A) 15% (B) 13% (C) 17% (D) 18%

Answer 1

Take the cost of the bill and add the tip percentage of the bill. That is:


`cost = bill + (bill *\% \: tip)`

or


`cost = bill(1 + \% \: tip)`

solve:


`19.47 = 16.50(1 + \% \: tip)`


`(19.47)/(16.50) = 1 + \% \: tip`


`1.18 = 1 + \% \: tip`


`\% \: tip = 0.18 = 18\%`

The tip was 18% of the bill.

Answer 2

She tipped 18 percent . 16.50x0.18= 2.97. 16.50+2.97= 19.47