In a ratio, the measurements must be in the same units. We can change feet to inches, or inches to feet. It is usually easier to convert to the smaller unit, since this avoids introducing more fractions into the problem.
Write the words that express the ratio.
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|
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Ratio of the rise to the run |
| Write the ratio as a fraction. |
runrise |
| Substitute in the given values. |
1 foot1 inch |
| Convert 1 foot to inches. |
12 inches1 inch |
| Simplify, dividing out common factors and units. |
121 |
So the ratio of rise to run is 1 to 12. This means that the ramp should rise 1 inch for every 12 inches of horizontal run to comply with the guidelines.