Question

A restaurant customer left ​$ as a tip. The tax was and the tip was ​% of the after tax cost. Which information is not needed to compute the bill after tax and​ tip? What was the total​ bill?

Answer 1

Complete question :

A restaurant customer left ​$0.90 as a tip. The tax was 8% and the tip was ​10% of the after tax cost. Which information is not needed to compute the bill after tax and​ tip? What was the total​ bill?

Answer:

The tax percentage

9.9

Step-by-step explanation:

Guven that :

Amount of tip left = 0.90

Tip left = 10% of after tax cost

Tax % = 8%

If tip left = 10% of after tax cost; then ;

If after tax cost = x

10% of x = 0.90

0.1x = 0.9

Hence the percentage tax isn't needed :

To obtain the total bill:

Let total bill = y

y = after tax cost and tip

Hence,

y = x + tip

y = x + 0.9

From : 0.1x = 0.9 ; x = 0.9/0.1 = 9

Hence,

Total bill:

y = 9 + 0.9

y = 9.9