A maths symbol is hidden in the below Bar Graph. Can you decipher it?

A large container is kept in open under the rain. Every passing hour, the water collected inside the container becomes double what it was.

In ten hours, the container is filled completely. Can you calculate how long would it have taken to be filled in half?

Five lovely ladies(Sophia, Isabella, Madison, Emma and Olivia) planned a picnic.

They each buy one thing each for the picnic.

Sophia, Emma and Olivia got a drink : orange-Juice, apple-juice, and mango-juice.
Olivia got the drink with the same letter as the one in her first name.
Emma loves mango-juice.
The other two bring some food : chocolates and pizza.
Also Madison is allergic to cheese.

So which ladies bought what ?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

What always comes into a house through the keyhole?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

What is the longest word in the dictionary?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain