What do you get if you add 2 to 100 four times?

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

Can you identify if it's a murder or a suicide ?

What part of the chicken has the most feathers?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

P is the father of Q and S is the son of R. T is the brother of P and has a daughter U. If R is the sister of P, then what is the relation between U, Q and S?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99