Difficulty: Easy
Correct Answer: 7254
Explanation:
Introduction / Context:
This question tests pattern recognition in number coding. Two two-digit numbers are being combined into a four-digit output using a consistent arrangement of digits. The goal is to identify that arrangement and apply it to a new pair.
Given Data / Assumptions:
Concept / Approach:
Break each two-digit number into tens and ones digits. Check how the four digits appear in the output. A common pattern is interleaving: first tens digit, then tens digit of second, then ones digit of first, then ones digit of second.
Step-by-Step Solution:
Take 65 and 46:
65 has digits: 6 (tens), 5 (ones)
46 has digits: 4 (tens), 6 (ones)
Output is 6456 = 6,4,5,6
So the rule is: (tens of first), (tens of second), (ones of first), (ones of second).
Now apply to 75 and 24:
75 gives 7 (tens), 5 (ones)
24 gives 2 (tens), 4 (ones)
Interleave: 7,2,5,4 → 7254
Verification / Alternative check:
Check 53 and 34: tens digits 5 and 3, ones digits 3 and 4, giving 5,3,3,4 → 5334. This matches, confirming the same rule, so 7254 is correct.
Why Other Options Are Wrong:
7542: keeps first number then reversed second, not interleaving.
7524: concatenates numbers directly.
7452: mixes tens/ones order incorrectly.
7245: swaps the last two digits incorrectly.
Common Pitfalls:
Concatenating without interleaving, reversing one number, or interleaving in the wrong sequence (ones first instead of tens first) are typical errors.
Final Answer:
7254
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