A person travelled 610 km in 9 hours. He travelled the first phase at 40 kmph and the rest at 90 kmph. The distance travelled in the first phase is

The first phase covered 160 km.

Let the time in the first phase at 40 kmph be t hours.

Then 40t + 90(9 - t) = 610.

40t + 810 - 90t = 610, so -50t = -200.

t = 4 hours, so first-phase distance = 40 x 4 = 160 km.

Thus 160 km was covered in the first phase.