Given a total of 34 clients, with 17 wanting mowing and 16 wanting weeding, and 5 clients wanting only watering, how many clients want both mowing and weeding?

Let $U$ be the total set of clients.
Let $M$ be the set of clients who require mowing.
Let $W$ be the set of clients who require weeding.
Let $Wa$ be the set of clients who require watering.

We are given:
Total clients, $N(U) = 34$.
Clients requiring mowing, $N(M) = 17$.
Clients requiring weeding, $N(W) = 16$.
Clients who only want watering, $N(Wa \text{ only}) = 5$. This means these 5 clients do not want mowing or weeding.

Step 1: Determine the