Suresh covers a distance of 34 km downstream in 4 hours 15 minutes and 19 km upstream in 3 hours 10 minutes in a luxury boat. What is the speed of the river stream?

উত্তর দেখান ও ব্যাখ্যা

উত্তর: (C) 1 km/h

ব্যাখ্যা

Downstream speed = 34 ÷ 4¼ = 8 km/h; upstream speed = 19 ÷ 3⅙ = 6 km/h. Speed of the stream = (8 − 6)/2 = 1 km/h.