Simplifying Rates to Solve Rate word problems It is often the case that before you can solve a rate word problem, you have to simplify the rate first. For example: If a wall that is 10 square metres requires 6 litres of paint, in order to paint the wall, then how many litres of paint would be needed to paint 25 square metres of that same wall. To simplify this rate, you have to divide the 6 litres by 10. Why? Because you first need to find out how many litres are needed for 1 square metre and then multiply this by 25. The worked problem looks like this: Simplify first: 6

10 Notice that this is not 10 divided by 6. Think logically and

use common sense.

6÷10=0.6 That is: To paint 1 square metre of wall, you'd need 0.6 litres of paint. ∴ to pain 25 square metres, you just multiply your answer by 25.

= 25 × 0.6 = 15.36Therefore, you would need at least 15.36 litres of paint to paint 25 square metres of the wall. As paint often comes in litre units, youwould logically need at least 16 litres of paint to give you enoughpaint to paint the entire wall.