Final answer:
To find the number of brownies Paul needs to bake to earn $10, we can use the concept of probability distribution. By setting up an equation, we can solve for the number of brownies using the price of one brownie and the probability of selling each brownie. The answer will be $10 divided by the product of (4/5) and the price of one brownie.
Step-by-step explanation:
To solve this problem, we need to use the concept of probability distribution. Paul expects to sell four out of every five brownies he bakes, which means he has a 4/5 probability of selling each brownie. He wants to earn $10 in total, so we need to find the number of brownies that will give him that earnings.
We can set up an equation to solve this problem. Let's say Paul bakes 'x' brownies. The expected earnings from selling 'x' brownies will be 4/5 times the price of one brownie times 'x'.
So, 4/5 * price of one brownie * 'x' = $10.
Simplifying the equation, we get:
(4/5) * (price of one brownie) * 'x' = $10.
To find the number of brownies, let's assume the price of one brownie is 'p'. So, our new equation becomes:
(4/5) * p * 'x' = $10
To solve for 'x', we can divide both sides of the equation by (4/5) * p:
'x' = $10 / [(4/5) * p].
Therefore, Paul needs to bake $10 / [(4/5) * p] brownies to earn a total of $10.