21) Look at this series: 31, 29, 24, 22, 17, . . . What number should come next?
a. 15
b. 14
c. 13
d. 12
22) Look at this series: 2, 4, 6, 8, 10, . . . What number should come next?
a. 11
b. 12
c. 13
d. 14
23) Look at this series: 80, 10, 70, 15, 60, . . . What number should come next?
a. 20
b. 25
c. 30
d. 50
24) Look at this series: 5.2, 4.8, 4.4, 4, . . . What number should come next?
a. 3
b. 3.3
c. 3.5
d. 3.6
25) Look at this series: 40, 40, 47, 47, 54, . . . What number should come next?
a. 40
b. 44
c. 54
d. 61
26) Look at this series: 2, 6, 18, 54, . . . What number should come next?
a. 108
b. 148
c. 162
d. 216
27) Look at this series: 1.5, 2.3, 3.1, 3.9, . . . What number should come next?
a. 4.2
b. 4.4
c. 4.7
d. 5.1
28) Look at this series: 21, 9, 21, 11, 21, 13, . . . What number should come next?
a. 14
b. 15
c. 21
d. 23
29) 28 25 5 21 18 5 14
a. 11 5
b. 10 7
c. 11 8
d. 5 10
e. 10 5
30) 2 3 4 5 6 4 8
a. 9 10
b. 4 8
c. 10 4
d. 9 4
e. 8 9