((I RAISED THE POINTS AND THIS IS MULTIPLE CHOICE))
Which sequences are geometric ?
CHOOSE ALL THAT APPLY

a) 100, 90, 80, 70, 60, . . . .
b) 320, 80, 20, 5, 1.25, . . . . .
c) 4, 9, 19, 24, 34, . . . .
d) 1/3, 2/3, 4/3, 8/3, 16/3, . . . .