Difficulty: Medium
Correct Answer: 510
Explanation:
Introduction:
This is a numerical reasoning question based on an artificial coding pattern rather than on ordinary multiplication. The symbol x does not represent simple multiplication in the usual sense. Instead, we are given two examples that follow a hidden rule, and we must deduce that rule and apply it consistently to a third case involving 85 and 12. Such questions test pattern recognition, numerical manipulation, and logical consistency.
Given Data / Assumptions:
We are told that 23 x 16 = 184 and 37 x 10 = 185 under a special rule. We must assume that the same rule applies uniformly to all expressions of the form a x b in this question. Our goal is therefore to find the value of 85 x 12 according to the same pattern. We also assume that there is a single, simple arithmetic relationship rather than multiple conflicting rules.
Concept / Approach:
The natural strategy is to try basic operations using the usual product of the two numbers in each example and see how that product is transformed into the given coded result. Often, coded operations involve adding or subtracting a constant, halving or doubling, or performing some combination of digits. We test these possibilities on the first pair and then see if the same relation works for the second pair. Once the rule is discovered, it can be directly applied to the new pair.
Step-by-Step Solution:
Step 1: Compute the ordinary product of 23 and 16. We get 23 * 16 = 368.Step 2: Compare this with the coded value 184. Notice that 184 is exactly half of 368, so 368 / 2 = 184.Step 3: Now test the same idea on the second example. Compute 37 * 10 = 370.Step 4: Half of 370 is 370 / 2 = 185, which matches the coded value given as 185.Step 5: Since the same rule, "take half of the usual product", works consistently for both examples, we adopt it as the underlying pattern: a x b = (a * b) / 2.Step 6: Apply this rule to 85 x 12. First find the ordinary product: 85 * 12 = 1020.Step 7: Now take half of 1020 to get 1020 / 2 = 510.Step 8: Therefore, 85 x 12 should be equal to 510 in this coding scheme.
Verification / Alternative check:
If we attempted any other simple transformation, such as adding or subtracting a constant or swapping digits, those rules would not match both original examples simultaneously. The halving rule is the only straightforward and consistent operation that converts 368 to 184 and 370 to 185. Hence, applying it to 85 and 12 is justified.
Why Other Options Are Wrong:
The value 511 would require adding 1 to the correct coded result without any justification from the pattern. The values 610 and 410 correspond to rearranging digits or subtracting wrong constants from the product, but such operations do not hold for the given base examples. The value 512 is also close numerically but does not arise from a consistent rule applied to all three pairs.
Common Pitfalls:
Learners sometimes invent overcomplicated digit operations before checking simple arithmetic transformations such as halving or doubling. Others may check a rule on only one example without verifying it on the second, which can lead to incorrect generalizations. Always confirm a suspected rule with all given examples.
Final Answer:
The value of 85 x 12 according to the pattern is 510.
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