Let the speed of train be ‘a’ and speed of bus be ‘b’.

Speed = distance/time

Roohi travels 300 km to her home partly by train and partly by bus. She takes 4 hours if she travels 60 km by train and the remaining by bus. If she travels 100 km by train and the remaining by bus, she takes 10 minutes longer

------- (1)

Also,

------- (2)

Multiplying eq1 by 5 and eq2 by 3 and subtracting eq2 from eq1

⇒ b = 80 km/hr

Thus, 60/a + 3 = 4

⇒ a = 60 km/hr