50. The sum of even numbers between 1 and 31 is :
A.6
B.128
C.240
D.512

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51. (51 + 52 + 53 +????+ 100) = ?
A.2525
B.2975
C.3225
D.3775

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52. The smallest prime numbers is :
A.0
B.1
C.2
D.3

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53. The sum of first five prime number is :
A.11
B.18
C.26
D.28

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54. How many prime numbers are less than 50 ?
A.16
B.15
C.14
D.18

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55. Which of the following is a prime number ?
A.33
B.81
C.93
D.97

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56. Which one of the following is not a prime number ?
A.31
B.61
C.71
D.91

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