Answer:
Monopolies create a market where you can only buy a product from one company. The monopoly can inflate the price to whatever they wish and no one can stop them because they all need the product and it is the only way to obtain it.
Think of it as this: if you were trying to buy a car but the only car manufacturer that existed was Honda. You want to buy a 2022 Honda Civic (around $22,000) but they are selling it for $45,000 which is nearly double the price. You have no choice but to pay it and get the car.
Hope that helps