How do you go from 98 to 720 using just one letter?

Can you find the 09 errors in the picture below?

What has many teeth, but cannot bite?

Do You See It?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

Solve the equation in the image by looking at the pattern closely.

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

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