The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E

Can you count the number of triangles in the picture below?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

A man dies of old age on his 25 birthday. How is this possible?

A man dies of old age on his 25 birthday. How is this possible?

Can you find out the missing number in the grid?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?

Which tank will fill first?

An office is divided into 8 cubicles. How many of the cubicles are painted if only 1/8 of the cubicles are painted?