using four eights (8) and a one (1) and one mathematical symbol , create the number 100

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

Which is the smallest number that you can write using all the vowels exactly once?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

What do you think with the below Picture ?

An old Woman left INR 33,333 to be divided equally among two fathers and two sons and each was to receive INR 11,111.
How was this possible?

Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?

I have branches, but no fruit, trunk or leaves. What am I?

A man calls his dog from the opposite side of a river. The dog crosses the river without a bridge or a boat and manages to not get wet. How is this possible?