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If A = \({128^{{{128}^{128}}}}\) then which of the following statement regarding A is incorrect?Statement 1: A is divisible by 2Statement 2: A is divisible by 3Statement 3: A is divisible by 61. Statement I2. Statement II3. Statement III4. None of these |
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Answer» Correct Answer - Option 4 : None of these Given: The given expression is A = \({128^{{{128}^{128}}}}\) Concept Used: Basic simplification and concept of unit digit Calculation: The given expression can be written as 128128 × 128 × 128………… × 128 times Again the expression can be simplified as 128128 × (128 × 128 × 128………… × 127 times) ∴ 128128 × (128 × 128 × 128………… × 127 times) = 1284 × 32 × (128 × 128 × 128………… × 127 times) Now, let 32 × (128 × 128 × 128………… × 127 times) = m ∴ 1284 × 32 × (128 × 128 × 128………… × 127 times) = 1284 × m Now, unit digit of 1284 × m ∴ 1284 × m = (8)4 × m For any value of n 8 4 × m always gives the unit digit as 6 ∴ 6 is divisible by 2 and 3 both and we know that the number divisible by 2 and 3 both will also divisible by 6 Hence, option (4) is correct |
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