The connecticut river flows at a ate of 4km/h for the length of a popular scenic route. In order for a cruiser to travel 60km upriver and then return in a total of 8 hr, how fast must the boat be able to travel in still water?

Question

anonymous · Answer

60 = (v-4)t1
60=(v+4)t2
t1+t2 = 8

anonymous · Answer

t1 is the time taken upstream, t2 downstream, and v is the speed of the boat

anonymous · Answer

ok. 
now what do i do?

dumbcow · Answer

use series of substitutions to find v
t1 = 8-t2
replace 8-t2 for t1 in first equation
60 = (v-4)(8-t2)
get t2 by itself in terms of v
replace that for t2 in 3rd equation

anonymous · Answer

uve got three variables nd three eqns
substitute t2 and (8-t1) in the first two eqns

anonymous · Answer

ok.... this is tricky.. lol