It would require 7 Cups of flour and 3 3/4 Cups of sugar.
First you get the whole numbers into fractions which 2 1/3 = 7/3. Then you multiply by 3 so 7x3=21, so your new result is 21/3 Which you can reduce into 7 Cups of Flour. The same can be done with the sugar. 1 1/4= 5/4. 5x3= 15, and your new result is 15/4 which you can reduce to 3 3/4 Cups of sugar.