Abatch of brownies requires 1/3 of a cup of cocoa powder. you want to make 4 batches. how many cups of cocoa powder do you need.

It is already given in the question that for making 1 batch of brownie it requires 1/3 of a cup of cocoa. Based on this inference we can get to the desired solution.
Then
Number of cups required to make 1 batch of brownie = 1/3
So Number of cups required to make 4 batches of brownie = 1/3 * 4
                                                                                               = 4/3 cups
                                                                                               = 1 1/3 cups
So 4/3 cups or 1 1/3 cups of cocoa is required to make 4 batches of brownies.