APPSC Group-I Prelims 2023 Paper II · Question 11

Question 11 of the APPSC Group-I Prelims 2023 Paper II (8 January 2023). Try it first, then open the answer and explanation.

1. Prelims 2023 · P-II · Q11 · Mental Ability & Reasoning · Numbers & Series

   Find the wrong term in the given series. 7, 12, 40, 222, 1742, 17390, 208608

   ఇచ్చిన సిరీస్‌లో తప్పు పదాన్ని కనుగొనండి. 7, 12, 40, 222, 1742, 17390, 208608

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   Answer: 1742

   సమాధానం: 1742

   The rule is multiply by 2, 4, 6, 8, 10, 12 and subtract 2, 8, 18, 32, 50, 72 (2n²): 7×2−2 = 12, 12×4−8 = 40, 40×6−18 = 222, 222×8−32 = 1744, 1744×10−50 = 17390, 17390×12−72 = 208608. So 1742 should be 1744.

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