1/4 because, imagine a 8 sliced pizza (you can see a 8 sliced pizza on google if u cant imagine it in your mind) take 2 pizza out then
u will have 3/4 of a pizza. Then take 1 more pizza out, and now u have 1/3 of a pizza and look closly at the pizza now you will see 1/4 because you have 4 sliced pizza left out of 1 pizza. so your brother will get 1/4 of pizza