**1. If someone scores a mark of, say, 72 out of 80 in a test, how is it changed to a percentage?**

Muliply the 72 by 100 and then divide by 80.

**2. What is the quickest way to increase, say, 120 by 5%?**

You could find 5% of 120 and then add it on to 120 but... the

QUICKESTway is to multiply 120 by 1.05

**3. How is the cost of an item increased to include the GST component?**

(Goods and Services Tax, GST, is a tax used in some countries − added to the price of goods or services bought.)Multiply the cost by 1.15 (this increases it by 15%)

**4. How do you calculate the cost of an item without GST?**

Divide the cost including GST by 1.15