Answer the following questions by selecting the correct/most appropriate option.

Rubina started her journey by car at 16:50 hours ad finished at 21:15 hours on the same day. The time taken in completing the journey is:

If n be any natural number, then by which greatest number is (n³ - n) always divisible?

When 15 is included in a list of natural numbers, their mean is increased by 2. When 1 is included in this new list, the mean of the numbers in the new list is decreased by 1. How many numbers were there in the original list?