Sequences and Series
 Find out the next term in the series 7, 11, 13, 17, 19, ...

 21
 23
 27
 None of these

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Given series is a consecutive prime number series.
Correct Option: B
Given series is a consecutive prime number series. Therefore, the next term will be 23.
 Find the missing term 6, ?, 21, 33, 48

 14
 20
 12
 18

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Series Pattern
+6, +9, +12, +15...Correct Option: C
Series Pattern
+6, +9, +12, +15....
∴ Missing term = 6 + 6 = 12
 Find the value of the expression 1  2 + 3  4 + 5  6 + 7 + .... upto 100 terms . ?

 150
 60
 100
 50

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(1  2) = 1
(3  4) = 1
(5  6) = 1
Correct Option: D
(1  2) = 1
(3  4) = 1
(5  6) = 1
and so on.
∴ Total terms of 1 will be 50.
∴ Answer = 1 x 50 = 50
 If A represents the arithmetic mean, H represents the harmonic mean and G represents the geometric mean, then what is the relation between them ?

 A x H = G
 A x H = G^{2}
 A/H = G^{2}
 A/H = G

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A = (a + b)/2,
1/H = (1/a + 1/b)/2
⇒ H = 2ab/(a +b),
G = √abCorrect Option: B
A = (a + b)/2,
1/H = (1/a + 1/b)/2
⇒ H = 2ab/(a +b),
G = √ab
∴ A x H = {(a + b)/2} x {2ab/(a + b)} = ab = G^{2}
∴ A x H = G^{2}
 4, 12, 36, ?, 324, 972

 108
 125
 215
 312

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Series pattern
Every next element = 3 x previous elementCorrect Option: A
Series pattern
Every next element = 3 x previous element
∴ Missing term = 3 x 36 = 108