The more of this there is, the less you see. What is it?

While house hunting in London, I came across a very good leasehold property Discussing the lease the landlady told me:

'The property was originally on a 99 years lease and two-thirds of the time passed is equal to four-fifths of the time to come. Now work it out for yourself and see how many years are to go!

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

In the formation, you can see a few arranged matchsticks. Can you form three squares by moving just three matchsticks?

There are are five things wrong with this sentence; only geniuses will be able to to spot all of the mitstakes

Doctor Alex and a bus driver John are both in love with the same woman named Olivia. The bus driver need to go for a long trip of 10 days, Before he left he gave Olivia 10 apples.

Can you count the number of squares in the figure below?

Solve the mathematical equation in the picture below.