The letters from A to Z are numbered from 1 to 26 respectively. If GHI = 1578 and DEF = 912, then what is ABC equal to?

• The problem states that letters A to Z are numbered 1 to 26, but the examples GHI = 1578 and DEF = 912 contradict this direct mapping (G=7, H=8, I=9 would be 789, not 1578).", "- Analyzing the pattern in GHI = 1578: G is the 7th letter, H is 8th, I is 9th. The number 1578 is formed by concatenating the position of the first letter (7) with the sum of the positions of the next two letters (8+9=17)? No, 7 and 17 makes 717. Let's look closer. 1578. G=7, H=8, I=9. 7+8=15, 8+9=17? No. Let's try: (G+H) = 15, (H+I) = 17? No, 1578. Maybe (G+H) = 15 and (H+I) = 17? 15 and 17 -> 1517. Not 1578. Let's re-read the options and the key. Key is 246. ABC. A=1, B=2, C=3. If the pattern is simply the positions, ABC=123. Not an option. If the pattern is sums: A+B=3, B+C=5 -> 35. Not an option. Let's look at DEF=912. D=4, E=5, F=6. 4+5=9, 5+6=11? No, 912. 4+5=9, 6? No. 4+5=9, 5+6=11. 911? No. Let's look at GHI=1578. G=7, H=8, I=9. 7+8=15. 8+9=17. 1517? No. 7*8=56? No. Let's look at the digits. 1, 5, 7, 8. G=7, H=8, I=9. 15 is 7+8. 78 is... H and I? 8 and 9? No, 78. So GHI = (G+H) concatenated with (H-1? No). Let's try: First two digits = Sum of first two letters. Last two digits = ? GHI: 7+8=15. Last two digits 78. H=8, I=9. 78 is not 89. 78 is G and H? 7 and 8. So GHI = (G+H) followed by (G and H)? 15 and 78. Yes. G=7, H=8. G+H=15. G=7, H=8. So 1578. Let's check DEF. D=4, E=5. D+E=9. D=4, E=5. So 945? But the value is 912. This hypothesis fails. Let's try another. GHI=1578. G=7, H=8, I=9. 15 = 7+8. 78 = ? 7*11? No. 1578 / 2 = 789. Ah! 789 is G, H, I. So GHI = 2 * (Position of G concatenated with Position of H concatenated with Position of I). 2 * 789 = 1578. Let's check DEF. D=4, E=5, F=6. Concatenation is 456. 2 * 456 = 912. This matches perfectly. So the rule is: Concatenate the position numbers of the three letters, then multiply by 2. For ABC: A=1, B=2, C=3. Concatenation is 123. 123 * 2 = 246. This matches option (d).", "- Step 1: Identify the position of each letter in the alphabet: A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8, I=9.", "- Step 2: Verify the pattern with GHI. Positions are 7, 8, 9. Concatenating them gives 789. Multiplying by 2 gives 1578, which matches the given value.", "- Step 3: Verify the pattern with DEF. Positions are 4, 5, 6. Concatenating them gives 456. Multiplying by 2 gives 912, which matches the given value.", "- Step 4: Apply the pattern to ABC. Positions are 1, 2, 3. Concatenating them gives 123.", "- Step 5: Multiply 123 by 2 to get 246, which corresponds to option (d).", "- Therefore, the correct answer is 246.