Answer:
You haven't explained the time for account A - we will assume 12 months or the answer is obvious:
for Acct(A) : I = 12.5 = A1 * .04 A1 = $312.50
for Acct(B) I = 11.25 = A2 * .03 * 5/4 = 300
Note that annual interest in B is .03 or I = .03 + .03 * 1/4 = .0375 for 15 mos.
11.25 = .0375 * A2 A2 = 300
Account A will have the greater principal