 
<translate> Abokinsa yana tuki 40 * 3 = mil 120. Saboda haka, Christina ta yi tafiyar mil 210, - 120 = 90. Tun da iyakar gudu shine 30 mil a kowace awa lokacin da Christina ke tuki, ta tuka 90 / 30 = 3 hours. Saboda haka, tana tuki na tsawon minti 3 * 60 = 180. Amsar ita ce 180. <eng> The friend drives 40 * 3 = 120 miles. Thus, Christina drives 210 - 120 = 90 miles. Since the speed limit is 30 miles per hour when Christina is driving, she drives for 90 / 30 = 3 hours. Thus, she drives for 3 * 60 = 180 minutes. So the answer is 180. 