If a projectile travels 3.00000 feet in one second, how far will it travel in 18 minutes

Answer 1

3.0000 ft/sec x 60 sec/min x 18 min= 3240 ft. Given that 18 has only 2 sig figs, the answer is 3200ft.

Answer 2

3.00000 ft/sec x 60 sec/min x 18 min = 3240 feet = 3200 feet (to 2 significant figures based on the value of 18 minutes which has only 2 sig. figs.)