The Brainliest Answer!
After 2 hours, A will cover distance = 35*2=70 km as distance = speed * time

After 2 hours B will cover 50*2=100km...

B stops after covering 100 km but car A continues! 
So if car A goes on then the first number that is a multiple of both the numbers is 350. So Both the cars will meet, when Car A covers 350 km!
Please mark it as best!
2 4 2
Not much satisfactory but still ok