Question

A and B and C are three villages on a highway. The distance between A and B is 18km. A motorbiker moved from A at speed of 10km/hr. At the same time , another man at village B started moving at 4km/hr. How long does it take the motorbiker to catch up to the man ? If they both reach C at the same time then what is the distance between C and B.​

Answer 1

Let A B = x miles = 18

B C = y miles

t1 = (18 + y) / 10 time for biker 1 to reach C

t2 = y / 4 = y / 4

t1 = t2 both bikers reach C at same time

(18 + y) / 10 = y / 4

72 + 4 y = 10 y

y = 12 distance from B to C

Check:

A C = 12 + 18 = 30 km

t1 = (18 + 12) / 10 = 3 hr

t2 = 12 / 4 = 3 hrs

So both meet at C in 3 hrs