What kind of band never plays music?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

What goes up but never comes down?

Manish and Manoj play 5 games of chess.
Both Manish and Manoj win the exact same number of games. There is no tie at all.

How?

Until it is measured, not known. Yet how you miss it when it has gone. What is it?

A 3 digit number is such that it's unit digit is equal to the product of the other two digits which are prime. Also, the difference between it's reverse and itself is 396.

What is the sum of the three digits?

Forwards I am heavy, backward I am not. What am I?

O_er_t_o_

Complete the missing letters of the given word.

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?