Which of the following infinite geometric series converges?
a1=5a_1 = 5a1=5, r=1.5r = 1.5r=1.5
a1=5a_1 = 5a1=5, r=−0.8r = -0.8r=−0.8
a1=5a_1 = 5a1=5, r=2r = 2r=2
a1=5a_1 = 5a1=5, r=−2r = -2r=−2