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.