What brings you down but never up?

How many times do a clock's hands overlap in a day ?

I have an eye but still cannot see.

Who am I?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

In a town, there are four houses located at different distances from each other. Following are the distances:

The third house is 60 meters apart from the first house.
The fourth house is 40 meters apart from the second house.
The third house is 10 meters nearer to the fourth house than it is to the second house.

Can you find out the distance between the fourth and the first house?

What runs around the whole yard without moving?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

What does this rebus mean?

O
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TIME