If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

Our product and our sum always give the same answer. Who are we?

A California farmer owns a beautiful pear tree. He supplies the fruit to a nearby grocery store. The store owner calls the farmer to see how much fruit is available for him to buy. The farmer knows the main trunk has 24 branches. Each branch has exactly 12 boughs and each bough has exactly 6 twigs. Since each twig bears one piece of fruit, how many plums will the farmer be able to deliver?

What does this rebus riddle mean?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

What does the below rebus riddle means?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

No matter how little or how much you use me, you change me every month. What am I?