Equations are solved on the basis of a certain system. On the same basis find…
2022
Equations are solved on the basis of a certain system. On the same basis find out the correct answer for the given equation. If 5472 → 9, 6342 → 6, 7584 → 6, then 9236 → ?
- A.
2
- B.
3
- C.
4
- D.
5
Attempted by 78 students.
Show answer & explanation
Correct answer: A
Concept: The digital root of a number is found by adding all its digits together, and if the sum has more than one digit, adding those digits again — repeating until a single digit remains. Many number-based coding puzzles encode each number by its digital root.
5472: 5 + 4 + 7 + 2 = 18, and 1 + 8 = 9, matching the given code 9.
6342: 6 + 3 + 4 + 2 = 15, and 1 + 5 = 6, matching the given code 6.
7584: 7 + 5 + 8 + 4 = 24, and 2 + 4 = 6, matching the given code 6.
9236: 9 + 2 + 3 + 6 = 20, and 2 + 0 = 2.
Cross-check: the digital root of a number always equals its remainder on dividing by 9 (taking 9 itself instead of a remainder of 0). Since 20 divided by 9 leaves a remainder of 2, this confirms the same result by an independent route. All three given equations reduce consistently under this one rule, so the coded value for 9236 is 2.