# Finding a percentage of a total amount without a calculator: Sales tax, commission, discount

In this lesson, we solve problems on finding a percentage of a total amount without a calculator involving sales tax, commission and discount.

Consider the following solved examples.

The sales tax on a $1050 computer system is$63. What is the sales tax rate?

### Solution

Step 1:

Price of the computer = $1050 Sales tax =$63

Step 2:

Rate of Sales tax = $\lgroup\frac{\$63}{\$1050}\rgroup \times 100$

= 6%

At a store, a $60 dress is sold at a discount of$12? What is the percentage of discount and sale price of the dress?

### Solution

Step 1:

Discount = $12 Marked price of dress =$60

Step 2:

Percentage of discount = $\lgroup\frac{\$12}{\$60}\rgroup \times 100 = 20\%$

Sales price of the dress = $60 −$12

= $48 Mike is a salesman who earns a base salary of$360 per week plus $567 as commission on sales. What was Mike’s percentage of commission and weekly salary if his total sales for the week were$6300?

### Solution

Step 1:

Total sales for the week = $6300 Commission on sales =$567

Step 2:

Percentage of commission = $\lgroup\frac{\$567}{\$6300}\rgroup \times 100 = 9\%$

Base salary = $360 =$360 + $567 =$927