I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

John went to meet his friend Jacob, but when he was about to reach the main gate, John notices that Jacob had a mighty dog who was fastened to the tree. The chain is long enough that it allows the dog to reach the main gate.

How can the John reach the main gate?

Can you solve the maths in the below-given picture equation?

What is the last thing you take off before bed?

With the help clues provided in the image, can you find the 5 digit key?

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?

Solve the counting riddle by identifying the number of triangles in the given picture.

What is the word or phrase?