What are the functional groups present in the structure of maltose?

The intermolecular potential energy for the molecules A, B, C and D given below suggests that :

The region in the electromagnetic spectrum where the Balmar series lines appear is :

If 75% of a first order reaction was completed in 90 minutes, 60% of the same reaction would be completed in approximately (in minutes) _______.

(Take : log 2 = 0.30; log 2.5 = 0.40)