What goes up but never comes down?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

What jumps when it walks and sits when it stands?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So i can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits

What does this mean?

CCCCCCC

Can anyone tell me a word in the English dictionary which has a silent 'z'?

In a fruit store, there was a unique weighing machine that was made to weigh only cherries and strawberries as they were priced the same.

Other fruits like watermelons or mango had different machines as they were expensive.

A man successfully buys watermelons at the price of cherries. How?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Can you find out the total number of triangles in the given figure?