If 1+9+8=1, what is 2+8+9?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

What has one eye, but can’t see?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

Which Travels Faster? Solve below famous picture riddle:

Count the number of triangles in the given picture.

What English word has three consecutive double letters?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Before Mount Everest was discovered, what was the highest mountain in the world?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?