Definition and working with Ratios, Basic Mathematics

The term, ratio, is frequently used whenever mathematical comparisons are involved. For example, in a distribution depot there is a standard that says the ratio of storage locations to the number of National Stock Numbers (NSNs) stored should not exceed 3:1 (read 3 to 1).

Ratios can be written either using a colon to separate the quantities being compared or as a fraction. To express any comparison as a ratio, first write the numbers as a fraction, and then reduce the fraction to its lowest terms.

Sometimes you need to apply a goal or a standard that is expressed as a ratio to determine the specific ratio for a particular situation. For example, you may have a standard of 1 computer for 4 employees; therefore, you may well need to use this standard to determine how many computers you will need for an office of 80 employees. In this case, you will know one value in your ratio (80 employees), but you will need to use the standard ratio to determine the other value in your ratio (the number of computers you will need, in this case 20).

To apply a standard ratio to determine the missing number for a particular situation, follow these steps:

Step 1. Divide the known quantity by its corresponding value in the standard ratio.

Step 2. Multiply the result from Step 1 by the other value in the standard ratio.

 

Examples,

1. If the DLA standard of supervisors to employees is 1:12, and if an organization has 360 employees, how many supervisors should it have?

The standard is 1 supervisor : 12 employees.

Step 1. 360 employees ÷ 12 employees = 30
Step 2. 30 • 1 supervisor = 30 supervisors

2. A certain solvent should be mixed with water in a ratio of 2:3. How many gallons of water should be added to 12 gallons of solvent?

The standard is 2 gallons of solvent : 3 gallons of water.

Step 1. 12 gallons of solvent ÷ 2 gallons of solvent = 6
Step 2. 6 • 3 gallons of water = 18 gallons of wate