TWO RHYMING RIDDLES

1)

I carry many letters,
And though it's strange to say,
I stay the same no matter
How many you take away.

2)
My first is a number, my second another,
And each I assure you will rhyme with the other.
My first you will find is 1/5 of my second,
And truly my whole 80 years may be reckoned.
Yet my first and my second, no less and no more,
When added together will make twenty-four.

Answers:

1. Mailman
2. Fourscore