Reasonable means that whatever decision was made is appropriate given the particular circumstances, and most would regard it as so.
Justified means that whatever decision was made is done for a good reason, in the interest of fairness.
There are times the words could be used interchangeably, and contexts where the difference is subtle. It all depends on the nature of the request or issue at hand.
I might use "justified" if I was angry about something, and was acting in response:
Was it polite to skip their wedding after they insulted me like that? No, but I think my decision was justified.
I might use "reasonable" if I think everyone would agree that there was nothing else that could be done:
Was I happy about missing their wedding so that I could go to my mother's funeral? No, but I think my decision was reasonable.
But there are contexts where either word will work just fine:
You said that you'd deliver the cake before noon, but it didn't get here until 3 o'clock. I think my request for a refund is reasonable/justified.
In that sentence, reasonable would work because most people would agree that a refund would be appropriate given the circumstances, and justified would work because the request is fair.
However you look at this question it's not easy to answer
Whereas ignoring it is the easy option
However, neither will keep me awake at night
I'd always use "whereas" as the second part of a comparison. "however" could also be used in this way. Often "however" would have a comma after it when used as the second part of a comparison.
I take "however" as something like "how ever you take the meaning of this" .
OTOH "whereas" is something like "in contrast to the previous opinion"
Best Answer
Daily, hourly, yearly and the like all started as adjectives, but centuries of use license their use as adverbs, too.
This makes some people uncomfortable, however; so you would probably do better to use them only as adjectives and employ the every construction when you want an adverbial:
What you will often see those uncomfortable people substituting is this construction:
I implore you not to emulate this pompous and awkward workaround.