Question

A person is going to fly from New York to London. If he leaves at 4:00 p.m., Eastern Standard Time and the flight lasts 4 1/2 hours, at what time should he set his watch when he arrives in London?

Answer 1

if they leave at 4 pm it is 5 hours ahead so it will be 7 pm

Answer 2

BST is 5hr ahead of EST.
The flight lasts 4.5hr.
The time when he arrives in London will be 9:30 ahead of the starting time.
4:00pm + 9:30 = 01:30, military time.