Question

a boat takes 3 hours 7.5 minutes to cover a distance of 30 km upstream and return back . when the speed of the stream is 4 km/hr . how much more time will it take in the same journey , if the speed of the stream increased to 5 km/hr? ​

Answer 1

$\huge\mathbb\red{ANSWER}$

Let speed of boat be x km/hr in still water

Let speed of stream be y km/hr

$➪ \frac{30}{x + y} = 3$

$➪x + y = 10 \: \: (10)$

$\frac{30}{x - y} = 5$

$➪x - y = 6 \: \: (2)$

FROM SOLVING (1) AND (2)

☞SO , X = 8KM/hr☜

HOPES IT HELPS YOU

Answer 2

Answer:

$\huge{\fbox\red{ANSWER}}$

Let speed of boat be x km/hr in still water

Let speed of stream be y km/hr

➪ \frac{30}{x + y} = 3➪

x+y

30=3

➪x + y = 10 \: \: (10)➪x+y=10(10)

\frac{30}{x - y} = 5

x−y30=5

➪x - y = 6 \: \: (2)➪x−y=6(2)

FROM SOLVING (1) AND (2)

☞SO , X = 8KM/hr☜

HOPES IT HELPS YOU