If the unknown value is x, then x = × 6 = 21.
Explanation:
- Since it is a double number line with a ratio, all the ratios of one number line to the other will remain equal for all the values along both the number lines. Assume the unknown value to be x.
- The ratio of the number on the first number line to the corresponding number on the second number line is calculated to be;
=
=
=
=
= 3.5. So
- We can also calculate x by the following method. As ratios are equal we can directly substitute the value to another ration. So
= 21.