Jamal and his brother were each given a banana for a snack. Jamal ate 2/3 of his banana. His brother ate 1/4 of his. How much more did Jamal eat than his brother?
Jamal ate 2/3 of his banana, or (2/3)*1 = <<2/3*1=2/3>>2/3 of a banana.
His brother ate 1/4 of his banana, or (1/4)*1 = <<1/4*1=1/4>>1/4 of a banana.
Thus, Jamal ate (2/3)*1 = <<2/3*1=2/3>>2/3 - (1/4)*1 = 8/12 - 3/12 = 5/12 more of a banana than his brother. Answer: \boxed{\frac{5}{12}}.