Letter Relations
1. The problem asks us to find the relationship that corresponds to SP given the pattern relating CT to RQ and AI to DF.
2. Let's analyze the pairs:
- CT to RQ
- AI to DF
3. To understand the pattern, we examine the positions of the letters in the alphabet:
- C is the 3rd letter and T is the 20th letter.
- R is the 18th letter and Q is the 17th letter.
4. So from CT to RQ:
- C (3) changes to R (18), which is $+15$ positions.
- T (20) changes to Q (17), which is $-3$ positions.
5. Now check AI to DF:
- A (1) to D (4) is $+3$ positions.
- I (9) to F (6) is $-3$ positions.
6. These differences are inconsistent, so let's check their reverse positions:
- For CT (3 and 20) to RQ (18 and 17), see if reversing or rearranging helps.
7. Alternatively, consider that the first letter is shifted by $+15$ in the first pair and $+3$ in the second; the second letter shifts by $-3$ in both pairs.
8. To find a matching consistent pattern, note that the second letter shifts backwards by 3 positions.
9. Check the options for SP, where S is 19 and P is 16:
- Second letter must go $-3$ positions: 16 - 3 = 13, which corresponds to M.
10. So for SP, second letter maps to M.
11. For the first letter, the shift isn't consistent, but two values were found: $+15$ and $+3$. Looking for $+3$ shift:
- S (19) + 3 = 22, which is V.
12. None of the options have second letters M or first letters V, so check the given options carefully:
- a) MD (M = 13, D = 4)
- b) DN (D = 4, N = 14)
- c) AD (A = 1, D = 4)
- d) AI (A = 1, I = 9)
13. Since the second letter of SP reduces by 3 (P at 16 -> M at 13), and None of the second letters in options is M, perhaps first letter shift of -3 is the key:
- For CT to RQ, C (3) to R (18): +15
- For AI to DF, A (1) to D (4): +3
Both second letters shift back by 3 in alphabet:
- T (20) to Q (17): -3
- I (9) to F (6): -3
14. So the second letter always moves back by 3.
15. SP's second letter P (16) moved back by 3 is M (13).
16. Check options for second letter M: only a) MD has M.
17. For the first letter S (19), first letters in the example pairs shift forward by 15 and 3; if we pick +3:
- S (19) + 3 = V (22), which is not in MD.
Alternatively, consider that the first letter moves back by 15 (since 3 + 15 = 18). So subtract 15 from S:
- 19 - 15 = 4, which corresponds to D.
18. So applying the first letter shift of $-15$ to S gives D.
19. Therefore, SP corresponds to DM or MD.
20. The options give MD, so the answer is MD.
Final answer: MD