I can write cow in 13 letters.

Can You?

Move four matchsticks to the below square to form three squares?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

When monkey rotate the gear, which mark will be hit 1 or 2 ?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

What is 3/7 chicken, 2/3 cat and 2/4 goat?

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

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?