4e^0.085t =50*(1.022)^t . . . e^0.085t=12.5*(1.022)^t . . . ln(...)=ln(....) . . . 0.085t=ln(12.5)+t*ln(1.022) . . . 0.085t -ln(1.022)t =ln(12.5) . . . ln(1.022)=0.021761491, so this become.... t*(0.085-0.021761491)=ln(12.5)=2.525728644 . . . 0.063238509t=2.525728644 . . . t=2.52..../ 0.063.....=39.93972476 . . . me spekt huever dreem up this thang...plan for anser=40