Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

In the image below, can you find the value of an angle(y)

While house hunting in London, I came across a very good leasehold property Discussing the lease the landlady told me:

'The property was originally on a 99 years lease and two-thirds of the time passed is equal to four-fifths of the time to come. Now work it out for yourself and see how many years are to go!

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

James ordered a fishing rod, priced at $3.56. Unfortunately, James is an Eskimo who lives in a very remote part of Greenland and the import rules forbid any package longer than 4 feet to be imported. The fishing rod was 4 feet and 1 inch, just a little too long, so how can the fishing rod be mailed to James without breaking the rules? Ideally James would like the fishing rod to arrive in one piece!

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?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

Can you find the missing number in the third row?
35 20 14
27 12 18
5 2 ?