Aturtle swims at a speed of 1584 meters per hour. a girl swims at a speed of 1380 millimeters per second. 10 mm = 1 cm 1 m = 100 cm how much faster does the girl swim than the turtle in centimeters per minute?

The girl's speed is 1380mm/sec * 1cm/10mm * 60sec/minute (since 1cm=10mm and 60 sec=1 minute)= 1380*60cm/10min= 1380*6cm/min
=8280 cm/min. For the turtle, we have 1584 m/hr * 1 hr / 60 min * 100 cm /1m (we have to make sure that they cross out, so e.g. for the hour we multiply it by 1 hr/60 min since the original hour is on the bottom)= 158,400cm/60min
=15840cm/6min
= 2640 cm/min
Since the girl is 8280 cm/min and the turtle is 2640 cm/min, we divide them to get 8280/2640= around 3.136 cm/min