Correct Answer - Option 2 : 80 km
Given :
A man travelled a distance of 1200 km in 16 hours. He travelled partly by car at a speed of 40 km/h, and partly by train at a speed of 80 km/h.
Concept used :
Time = Distance/speed
Calculations :
Let the distance travelled with 80 km/h speed be 'x' km
Let the distance travelled with 40 km/h speed be '1200 - x' km
Time for x km = x/80
Time for 1200 - x km = (1200 - x)/40
Total time = (x/80) + (1200 - x)/40
⇒ (x/80) + (1200 - x)/40 = 16
⇒ x = 1120 km
Distance travelled by car = 1200 - x
⇒ 1200 - 1120
⇒ 80 km.
∴ Option 2 will be the right answer.
