Arowing team rowed 90 miles while going with the current in the same amount of time as it took to row 10 miles going against the current. the rate of the
current was 4 miles per hour. find the rate of the rowing team in still water.
rate of the team in still water:

The speed in still water is 5 miles per hour.

Step-by-step explanation:

distance with current = 90 miles

distance against current = 10 miles

speed in still water = s

speed of current = 4 mph

speed with current = s + 4

speed against current = s - 4

time = t

speed = distance/time

distance = speed * time

With current:

90 = (s + 4) * t

Against the current:

10 = (s - 4) * t

We have a system of equations:

90 = (s + 4) * t

10 = (s - 4) * t

90 = ts + 4t

10 = ts - 4t

Subtract the second equation from the first equation.

80 = 8t

10 = t

t = 10

10 = t(s - 4)

10 = 10(s - 4)

1 = s - 4

s = 5

The speed in still water is 5 miles per hour.

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.

a

step-by-step explanation:

its wrong