Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

What runs around the whole yard without moving?

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

If you say my name, I will no longer exist. What am I?

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?

Why is 6 afraid of 7?

I am soft and cuddly that soothe your heart. But, If you pick my last name I am going to tear you all apart. Who am I?