The ratio of the speed of a boat downstream and speed of the stream is 9:1. If the speed of the current is 3 km per hr, find the distance travelled by the boat upstream in 5 hours.

Question

নিচের অপশন গুলা দেখুন

• 109 km
• 98 km
• 100 km
• 105 km

Answer 1

সঠিক উত্তর হচ্ছে: 105 km

ব্যাখ্যা:

Let the speed of boat in still water is ‘x’ km/hr & that of stream is ‘y’ km/hr.
Then, ATQ
(x+y)/y = 9/1 9y = x + y
x = 8y
y = 3 km/hr
So, x = 24 km/hr
Upstream speed = 24-3 = 21 km/hr
Hence, distance travelled upstream in 5 hours = 21*5 = 105 km.