The smallest possible three - place decimal is: 

The side of a square is 8 cm. If a square is made by joining the mid points of each sides of this square and this process goes up to infinity. Calculate the sum of areas of all the squares made.

Simple interest on a certain sum is equal to the sum itself. find the time if rate of interest and time are numerically equal.

The average age of a class of 40 students and a teacher reduces by 0.5 years, if we exclude the teacher. If the initial average age is 18 years, then what is the age of the teacher?

A person has some amount with him. 25% of it is stolen in a bus, 10% is lost through a hole in the pocket, 50% of remainder is spent on food. He then purchases a book worth Rs. 26 from the remainder. He walks back home because all his money is over. What was the initial amount?

A runner starts running from a point at 6:00 am with a speed of 8km / hr. Another racer starts from the same point at 8:30 am in the same direction with a speed of 10km / hr. At what time of the day (in P.M.) will the second racer will overtake the other runner? 

On dividing a certain number by 342 we get 47 as remainder. If the same number is divided by 18, what will be the remainder?

What approximate value should come in the place of question mark (?) in the following question?
 (8423 + 3120 + 6543) ÷ (1536 + 377 + 189) = ?