Ratios
A ratio compares two numbers or two quantities that are measured with the same unit. The ratio of
a to
b is written
a to b,ba,ora:b.
In this section, we will use the fraction notation. When a ratio is written in fraction form, the fraction should be simplified. If it is an improper fraction, we do not change it to a mixed number. Because a ratio compares two quantities, we would leave a ratio as
example
Write each ratio as a fraction:
- 15 to 27
- 45 to 18
Solution
1. |
|
|
15 to 27 |
Write as a fraction with the first number in the numerator and the second in the denominator. |
2715 |
Simplify the fraction. |
95 |
2. |
|
|
45 to 18 |
Write as a fraction with the first number in the numerator and the second in the denominator. |
1845 |
Simplify. |
25 |
We leave the ratio in (2) as an improper fraction.
example
Write each ratio as a fraction of whole numbers:
1.
4.8 to 11.2
2.
2.7 to 0.54
Answer:
Solution
1. 4.8 to 11.2 |
|
Write as a fraction. |
11.24.8 |
Rewrite as an equivalent fraction without decimals, by moving both decimal points 1 place to the right. |
11248 |
Simplify. |
73 |
So
4.8 to 11.2 is equivalent to
73.
2.
The numerator has one decimal place and the denominator has 2. To clear both decimals we need to move the decimal 2 places to the right.
2.7 to 0.54 |
|
Write as a fraction. |
0.542.7 |
Move both decimals right two places. |
54270 |
Simplify. |
15 |
So
2.7 to 0.54 is equivalent to
15