How Do you Find a ratio?

Answer 1

A ratio is expressed as the relationship of whole numbers or decimals. The numbers can determine percentages, scales, parts of a solution, or output per input in gears. The ratio is simply a multiple and can be changed to other ratios just as fractions are changed, by multiplication of both sides.

Some examples of ratios are:

• If you need to mix 1 part whitewash with 2 parts water, the ratio is 2:1
• If a gearbox input shaft makes 1 revolution causing the output to make 2.6 revolutions, the ratio is 1:2.6
• If a drawing of a house is drawn on paper, it is drawn much smaller but to scale with the real house dimensions. If the drawing is 120 times smaller than the house, then the scale is 1:120
• If 26 out of every 100 adults smoke cigarettes, then the ratio is 26:100

In the final two examples, you can express the ratio scale as a fraction (1/120th scale) and the percentage of smokers as 26% (26 percent).

To simplify a ratio, divide both sides by the smaller number. E.g. the ratio of 300 to 10 (300:10) is 30 to 1, and the ratio of 10:20 equals the ratio 1:2 (1/2).