2.a is 25 and B is 28, which is lower than B (28-25)/28 = 3/28 =10.714%.

3.a is 3500 less than B's 1/4. B is (3500+350)/(1/4) =15400.

4.a is 3500 more than B's 1/4. B is (3500-350)/(1/4) =12600.