Insert the missing number.

1.	16, 33, 65, 131, 261, (....)
	A. 523 B. 521 C. 613 D. 721 Answer & Explanation Answer: Option A Explanation: Each number is twice the preceding one with 1 added or subtracted alternatively. So, the next number is (2 x 261 + 1) = 523. View Answer Workspace Report Discuss in Forum

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2.	10, 5, 13, 10, 16, 20, 19, (....)
	A. 22 B. 40 C. 38 D. 23 Answer & Explanation Answer: Option B Explanation: There are two series (10, 13, 16, 19) and (5, 10, 20, 40), one increasing by 3 and the other multiplied by 2. View Answer Workspace Report Discuss in Forum

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3.	1, 4, 9, 16, 25, 36, 49, (....)
	A. 54 B. 56 C. 64 D. 81 Answer & Explanation Answer: Option C Explanation: Numbers are 12, 22, 32, 42, 52, 62, 72. So, the next number is 82 = 64. View Answer Workspace Report Discuss in Forum

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4.	2, 4, 12, 48, 240, (....)
	A. 960 B. 1440 C. 1080 D. 1920 Answer & Explanation Answer: Option B Explanation: Go on multiplying the given numbers by 2, 3, 4, 5, 6. So, the correct next number is 1440. View Answer Workspace Report Discuss in Forum

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5.

8, 7, 11, 12, 14, 17, 17, 22, (....)

A. 27 B. 20 C. 22 D. 24 Answer & Explanation Answer: Option B Explanation: There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22) increasing by 3 and 5 respectively. View Answer Workspace Report Discuss in Forum 6.  11, 13, 17, 19, 23, 29, 31, 37, 41, (....) A. 43 B. 47 C. 53 D. 51 Answer & Explanation Answer: Option A Explanation: Numbers are all primes. The next prime is 43. View Answer Workspace Report Discuss in Forum 7.  8, 24, 12, 36, 18, 54, (....) A. 27 B. 108 C. 68 D. 72 Answer & Explanation Answer: Option A Explanation: Numbers are alternatively multiplied by 3 and divided by 2. So, the next number = 54 ÷ 2 = 27. View Answer Workspace Report Discuss in Forum 8.  2, 6, 12, 20, 30, 42, 56, (....) A. 61 B. 64 C. 72 D. 70 Answer & Explanation Answer: Option C Explanation: The pattern is 1 x 2, 2 x 3, 3 x 4, 4 x 5, 5 x 6, 6 x 7, 7 x 8. So, the next number is 8 x 9 = 72. View Answer Workspace Report Discuss in Forum 9.  4, -8, 16, -32, 64, (....) A. 128 B. -128 C. 192 D. -192 Answer & Explanation Answer: Option B Explanation: Each number is the proceeding number multiplied by -2. So, the required number is -128. View Answer Workspace Report Discuss in Forum 10.  7, 26, 63, 124, 215, 342, (....) A. 481 B. 511 C. 391 D. 421 Answer & Explanation Answer: Option B Explanation: Numbers are (23 - 1), (33 - 1), (43 - 1), (53 - 1), (63 - 1), (73 - 1) etc. So, the next number is (83 - 1) = (512 - 1) = 511. 11.  5, 10, 13, 26, 29, 58, 61, (....) A. 122 B. 64 C. 125 D. 128 Answer & Explanation Answer: Option A Explanation: Numbers are alternatively multiplied by 2 and increased by 3. So, the missing number = 61 x 2 = 122. View Answer Workspace Report Discuss in Forum 12.  15, 31, 63, 127, 255, (....) A. 513 B. 511 C. 517 D. 523 Answer & Explanation Answer: Option B Explanation: Each number is double the preceding one plus 1. So, the next number is (255 x 2) + 1 = 511. View Answer Workspace Report Discuss in Forum 13.  1, 8, 27, 64, 125, 216, (....) A. 354 B. 343 C. 392 D. 245 Answer & Explanation Answer: Option B Explanation: Numbers are 13, 23, 33, 43, 53, 63. So, the missing number is 73 = 343. View Answer Workspace Report Discuss in Forum 14.  3, 7, 6, 5, 9, 3, 12, 1, 15, (....) A. 18 B. 13 C. -1 D. 3 Answer & Explanation Answer: Option C Explanation: There are two series, beginning respectively with 3 and 7. In one 3 is added and in another 2 is subtracted. The next number is 1 - 2 = -1. View Answer Workspace Report Discuss in Forum

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