The distance between Point A and Point B is 20 km.

Alice and Serena left Point A at 1100 and drove towards Point B at speeds of 18 km/h and 24 km/h respectively.

When Serena completed `3/4` of her journey, she took a break till Alice caught up with her before resuming her drive to Point B.

How long was Serena's break?

Note to students:

1. Give your answer in minutes
2. Round your answer off to 2 decimal places