Question

A car starts from a for b travelling 20 km an hour.1 1/2 hours later another car starts from a and travelling at the rate of 30 km an hour reaches b 2 1/2 hours before the first car. Find the distance from a to b.

Answer 1

first car

time=11/2

speed=20

distance=11×2/20=11/10

Answer 2

Answer:

Step-by-step explanation:

let’s call them car1 and car2.

Had they start together car2 would have reached (1.5+ 2.5) = 4 hour before car1.

Now in 4 hours car1 covers (20 X 4) = 80 km. So, car2 lead by 80 km in this time. Now, car2 get lead of (30–20) = 10 km/hour. So , to get 80 km lead they have to go for 80/10 = 8 hour. So car2 has taken 8 hour to go from A to B.

So, distance between A and B is (8 X 30) = 240 km.