Mathematics: Aferry departs from a port along the sands river at 10: 00 am. the ferry travels at a speed of 15 mph in still water and returns to port at 2: 00 pm. if the ferry trip upstream takes twice as long as its return trip downstream, what is the speed of the river’s current

Aferry departs from a port along the sands river

joejoefofana

15.01.2022

Speed of river's current = 5 mph

Step-by-step explanation:

Let 'd' be the distance covered

Let x be the speed of the rivers current

Speed upstream = 15-x

speed downstream = 15+x

Time = distance / speed

time upstream = $\frac{d}{15-x}$

time downstream = $\frac{d}{15+x}$

the ferry trip upstream takes twice as long as its return trip downstream

$\frac{d}{15-x}$ = $\frac{2d}{15+x}$

divide both sides by d

$\frac{1}{15-x}$ = $\frac{2}{15+x}$

cross multiply

15+x= 2(15-x)

15+x= 30-2x

Add 2x on both sideds

15+3x= 30

subtract 15 from both sides and divide by 3

3x=15

x=5

Speed of river's current = 5 mph

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angelaguero9877

06.04.2023

Step-by-step explanation:

I assume by c you mean cm

1m = 100cm

300m x 100 = 30,000cm

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