Algebra homework

Question

Josh can row a boat at an average speed that is eight times as fast as his average swimming speed. It takes him 80 minutes to swim 4 laps in a lake than to row 4 laps. How fast is his average swimming speed In laps per minute?

Answer 1

r=8s

80 more minutes to swim 4 laps than to row 4 laps

what is his swimming speed n laps per minute??

d=rt = laps = speed times time

4 = (80+t)s = t(8s) = 8ts=ts+80

8ts = 4

ts = 1/2

ts +80s =4

s=7/160= swim speed, r=7/20 = rowing speed

r= .35 lap per minute, s= .04375 lap per minute

t=1/.0875 minutes= about 11.43 minutes to row 4 laps

t+80 = 91.43 minutes to swim 4 laps