Can you make four (4) nines (9) equal 100?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

What has many keys but can’t open a single lock?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Name a key which is hardest to turn.

In a stable, there are men and horses. In all, there are 22 heads and 72 feet. How many men and how many horses are in the stable

Find a 9-digit number, which you will gradually round off starting with units, then tenth, hundred etc., until you get to the last numeral, which you do not round off. The rounding alternates (up, down, up ...). After rounding off 8 times, the final number is 500000000. The original number is commensurable by 6 and 7, all the numbers from 1 to 9 are used, and after rounding four times the sum of the not-rounded numerals equals 24.

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

There are three boxes of different sizes with three cupcakes inside each of the boxes in Christina's kitchen. At night her daughter wakes up and goes to the kitchen. She opens a box and eats all three cakes.

But in the morning Christina finds out that each box still had three cupcakes. How?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?