Question

Write an expression using fractions to show how to determine the amount that a person will pay 20% of $12.00 for a tip

Answer 1

20/100 = x/12

The 20/100 in the expression represents the 20%. The x in this scenario is the unknown amount in which the person will tip. The /12 is the cost of the original price. So, in order to find the value of x, you would need to cross multiply. 
x = $2.40
The total cost would be $2.40 + $12.00 = $14.40