To find the mechanical advantage (MA) of a lever, you can use the formula:
\[ \text{Mechanical Advantage (MA)} = \frac{\text{Distance from Fulcrum to Effort}}{\text{Distance from Fulcrum to Load}} \]
In this case, the distance from the fulcrum to the effort is 15 meters and the distance from the fulcrum to the load is 5 meters.
Substituting the values into the formula:
\[ \text{MA} = \frac{15 \text{ m}}{5 \text{ m}} = 3 \]
So the mechanical advantage is 3.