Again, model can be used, but I prefer another method that does away with that hassle of drawing... The trick is to make the numerators of the fractions that are equal, the same. The resulting denominators would tell us how many units each have at first:

Fraction of James left --> 3/4

Fraction of Bond left --> 1/3 = 3/9 (make numerator same as James' left fraction)

James --> 4 units (look at the denominator)

Bond --> 9 units (remember not to use the old fraction 1/3)

Total units --> 13

13 units --> 728

1 unit --> 56

4 units --> 56 x 4 = 224

This is a fairly standard question with a little trick in that the fractions given are not equal, but rather the "left" fractions are equal