How many words can a pen with half refill write?

A patient was diagnosed with some ailment. He was given five different tablets to take at night at an interval of 15 minutes.

How long will it take the patient to consume all the five tablets?

What animal walks on four legs in the morning, two legs during the day, and three legs in the evening?

Oedipus, the king of Thebes, figured out the answer to the riddle:

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 will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

What has no start, end, or centre?

I have eight fingers and two thumbs but I do not live. What Am I?

How can one talk without saying a single word?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag