Can you make a six-letter word using the letters N, A and B ?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

What number comes next in this sequence:
7 8 5 5 3 4 4 _

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

My thunder comes before the lightning; my lightning comes before clouds; my rain dries all the land it touches. What am I?

Identify the movie name through below Rebus containing Pi Mouse and coconut tree..

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Queen Elizabeth organised a royal party.

To Avoid uninvited guest royal family set a password.
Jack (an uninvited person) plan to enter the party. He stand nearby the door.

First guest comes, the security person said 'twelve' and guest replied with six.
Second guest comes , the security person said 'six' and guest replied with 'three'.

Jack thought is enough and he walked to the entry point. The security person said 'eight' , Jack replied smilingly 'four'.
He was immediately thrown out of the party. why ?

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?