To find the total weight of the vegetables, we first need to calculate the weight in pounds.
Each basket contains \( 1 \frac{1}{2} \) lb of vegetables, which can be converted to an improper fraction:
\[ 1 \frac{1}{2} = \frac{3}{2} \text{ lb} \]
Lars has 10 baskets, so we multiply the weight of vegetables in one basket by the number of baskets:
\[ 10 \times \frac{3}{2} = \frac{30}{2} \]
Now, simplify \( \frac{30}{2} \):
\[ \frac{30}{2} = 15 \text{ lb} \]
Since 15 is a whole number, it can be expressed as a mixed number:
\[ 15 = 15 \frac{0}{1}, \text{ or simply } 15 \]
Thus, the total weight of all the vegetables in the baskets is \( 15 \) lb.