42. Someone asked Uncle Wang: "How many pots of flowers are there in your garden?" Uncle Wang said: "Half are roses, a quarter are lilies, one seventh are peonies, and less than 6 pots are roses." Therefore, Uncle Wang's garden has $\qquad$ pots of flowers.
Answer: 28.
Solution: Let the total number of flowers in Grandpa Wang's garden be $x$ pots, and the number of roses be $a$ pots. From the given conditions, we know that $x, a$ are natural numbers, and $1 \leq a<6$. Then

we get
$$
\begin{array}{c}
\frac{x}{2}+\frac{x}{4}+\frac{x}{7}+a=x, \\
x=\frac{28}{3} a .
\end{array}
$$

Since
$x, a$ are natural numbers, and $1 \leq a<6$,

we have
$$
a=3,
$$

thus
$$
x=28 \text {. }
$$

Therefore, the garden has a total of 28 pots of flowers.