Let's say you have three different things you want to make, like baking a cake, washing your clothes, and taking a bath. Each thing needs a certain amount of water, electricity, and gas. But the problem is, you only have enough of each utility to complete two of the tasks.
This is called the three utilities problem. Basically, you have to decide which two things you want to do, and sacrifice the third thing because you don't have enough resources to do all three.
It's like if you have three friends over and you only have two pieces of candy left. You have to decide which two friends get the candy, and the third friend doesn't get any. It's not fair, but it's the only way to make sure everyone gets something.
In the case of the three utilities problem, you have to balance your priorities and decide which tasks are the most important to you. Maybe you need clean clothes for work more than you need to take a bath, so you'll use the water and electricity for washing clothes and baking a cake for a celebration.
Overall, the three utilities problem is just a way to remind us that we can't always have everything we want, and sometimes we have to make tough decisions and prioritize what's most important.