When we see 2 but call 10?

How many bananas can you eat if your stomach is empty?

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

Can you place three balls such that the equation shown in the picture holds true?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

How many people must be gathered together in a room, before you can be certain that there is a greater than 50/50 chance that at least two of them have the same birthday?

I know a nine-letter word having only one vowel.
Do you ?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

In a rainy season, one day 3 huge ladies walked under a normal-sized umbrella.
The umbrella is not huge enough to accommodate all 3 ladies yet not a single lady got wet. Why?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.