When we see 2 but call 10?

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

In a classic wine shop, the list of three most popular wines are:
- The cost of 1 French wine bottle: 500$
- The cost of 1 German wine bottle: 100$
- The cost of 20 Dutch wine bottles: 100$

John entered the wine shop and he needs to buy
- All three types of wine bottles.
- Needs to buy Dutch wine bottles in multiples of 20.
- Need to buy 100 wine bottles in total.

John has only 10000$. How many wine bottles of each type, John must buy?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?

What goes up but never comes down?

What does the below mathematical rebus mean?

What begins with T, ends with T, and has T in it?

How many times in a given day, minutes and hour clock comes in a straight line ?

You are given with the following sum. Each of the letters can be decoded as a digit. If we tell you that D = 5, then can you solve it entirely?

DONALD
+GERALD
=ROBERT

What always comes into a house through the keyhole?