What occurs twice in a week, once in a year but never in a day?

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

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

What goes up but never comes down?

A girl says this to her best friend: “I was born in 1955, and I celebrated my 17th birthday last weekend.” Her best friend thinks she’s lying, but she’s actually correct. How is that possible?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

There is a hypothetical state between the USA and Mexico border 'Tango'.
Here 70 percent of the population have defective eyesight, 75 percent are hard of hearing, 80 percent have Nose trouble and 85 percent suffer from allergies, what percentage (at a minimum) suffer from all four ailments?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Andrew sees a very rare bird named "Ruppell's vulture". Soon Andrew was dead. Can you explain the mystery, Mr. Sherlock?