Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Fate has decided that you will only be pleased to meet me when you need me

Maybe that is why, when I am working, I start working

However annoying I may be to the regulars, the little ones are always inspired

I will always be waiting if you try to reach me

How many of you can guess my name, let me see

I have teeth but i don't bite. Who Am I ?

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

Solve below popular number sequence
314 159 265 358 979 323 846 ?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

In particular commonwealth games, a female participant won silver and gold medals for a single event.

How can this be possible?

John was running from 40 thieves. John has got 3 gold boxes which weigh as 4kg, 2kg, and 1kg respectively. A witty man asked John to stay with him for seven days in exchange for 1kg gold per day. John needs to stay there for seven days and also do not want to give the witty man any advance. How can John pay for his seven days stay?

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?