Can you make a fire with just a single stick?

Our product and our sum always give the same answer. Who are we?

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?

The more of this there is, the less you see. What is it?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Using eight eights and addition only, can you make 1000?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?

Can you name four days which start with the letter 'T'?

Can you calculate the probability of getting a sum of six when a dice is thrown twice?