b) A tree that is 3 m tall casts a shadow that is 2 mlong.At the same time, a nearby building casts a shadow that is 25 m long.How tall is the building?

## Step 1: Setting up the proportion<br />### We can set up a proportion relating the height of the tree to its shadow length, and the height of the building to its shadow length. Let $x$ be the height of the building. The proportion is $\frac{3}{2} = \frac{x}{25}$.<br /><br />## Step 2: Solving for x<br />### To solve for $x$, we can cross-multiply: $2x = 3 \cdot 25$. This simplifies to $2x = 75$.<br /><br />## Step 3: Finding the height<br />### Dividing both sides by 2, we get $x = \frac{75}{2} = 37.5$.