Since AAB is 3-digit number and CDA is 3-digit number, there are only 2 possibilities for A: A= 1 or A= 2. But A is the last digit of the number CDA, which is multiple of 4; so it leaves only one possibility for A to be 2: A = 2. Then B = 3 or B = 8. Case 1). If B = 3, then 4 * 223 = 892; so, C= 8 and D= 9. Case 2). If B = 8, then 4 * 228 = 912; so, C= 9 and D= 1. The condition C < D is satisfied in case 1 ONLY; so, case 2) is denied. Therefore, A+B+c+D = 2+3+8+9 = 22. ANSWER