Question

A boat can cover 10km up the atream and 5 km down stream in 6 hour if the speed of the stream is 1.5 kmph find the sleed of the boat to return

Answer 1

Here on solving, we get a quadratic equation.

Out of its two roots, one is positive and other is negative. Since speed cannot be negative, we consider the positive root.

So, your answer is 3.5 kmph