Number Series - SBI PO Preliminary Exam Challenge

1) What is the sum of 100 terms of the series
1 - 2 + 3 - 4 + 5 - 6 + … ?
a) 100
b) 50
c) 550
d) Data inadequate
e) None of these


2) The number of terms in an A.P. is even, the sum of odd terms is 63 and that of even terms is 72 and the last term exceeds the first term by 16.5. Find the number of terms :
a) 8
b) 12
c) 9
d) 10
e) None of these

3) Find the next term of following series:
276, 140, 68, 36 ?
a) 16
b) 12
c) 15
d) 14
e) None of these


 4) Find the next number of the following series:
672, 560, 448, 336, 224?
a) 122
b) 112
c) 142
d) 182
e) 162

5)What should come in place of question mark?
1721, 2190, 2737, 3368?
a) 4089
b) 5089
c) 3089
d) 2089
e) None of these

Directions : (Q. 6 to 10): In each of the following number series, a wrong number is given, find out that number.
6) 3 9 23 99 479 2881 20159
a) 9
b) 23
c) 99
d) 479
e) 2881


 7) 1 3 6 11 20 39 70
a) 3
b) 39
c) 11
d) 20
e) 6


8) 50 51 47 56 42 65 29
a) 51
b) 47
c) 56
d) 42
e) 65


9) 2 13 27 113 561 3369 23581
a) 27
b) 13
c) 113
d) 561
e) 3369

10) 7 4 6 9 20 52.5 160.5
a) 6
b) 4
c) 20
d) 9
e) 52.5