Speed and time question

Two towns are exactly 100 km apart. Suresh leaves City-A at 3 pm driving at 30 km/hr. After 30 minutes, at 3:30 pm, Ramesh leaves City-B driving at 60 km/hr.

When they meat each other, how far they will be from City-A ?
Solution:

Suresh starts 30 minutes before Ramesh.

In 30 min he would have traveled = 15 km.

When both of them are moving toward each other their relative speed is  = 90 km/hr (30+60)

The distance between them is =  85 km (15 km is already traveled by Suresh).

Time taken to cover 85 km @ 90 km/hr = 85/90 hrs = 56.67 min

Distance traveled by Suresh in 56.67 min = 28.34 km.

Total distance from A = distance traveled by Suresh = 15 + 28.34 = 43.34 km.