Suppose the growth of a tumor with radius r(t) (t = time in weeks) is described by the equation r′(t)=k1t+n(t) where n(t)=2k2, k1=1, and k2=1.5. If the tumor's initial radius is r(0)=0.25 cm, which of the following is the closest to the time it would take for the tumor to reach a radius of 15 cm?

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.