Question -
Answer -
Let speed of the stream be x km/hr,
Speed of the boat upstream = (18 тАУ x) km/hr
and Speed of the boat downstream = (18 + x) km/hr
Distance = 24 km
┬а
48x = 324 тАУ x2
x2 + 48x тАУ 324 = 0
x2 + 54x тАУ 6x тАУ 324 = 0
x(x + 54) тАУ 6(x + 54) = 0
(x тАУ 6) (x + 54) = 0
x тАУ 6 = 0 or x + 54 = 0
x = 6 or x = тАУ 54
Since speed cannot be negative
Speed of stream, x = 6 km/hr