How many words can a pen with half refill write?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

Find the value of "?" in the ball picture Riddle below:

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

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

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?