Solution:

Concrete floors are very hard to crack

Solution:

The second statement
(Two statements here are false.)

Solution:

Move the 6 up just a little bit.
2pow(6) -63 =1

Solution:

It is not possible to guess only three fruits correctly: the fourth fruit is then correct too! So nobody has guessed three fruits correctly and 123-43-39-31 = 10 people have guessed four fruits correctly.

Solution:

Silence

Solution:

60.

100 years in a century, 365 days in a year, 24 hours in a day, 60 minutes in an hour, & 60 seconds in a minute.

Solution:

Forest

Solution:

An apple a day keeps the doctor away!

Solution:

RobInHood

Solution:

A Hole