How many times can you subtract the number two from the number fifty?

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!

Prove that twice of ten is the same as twice of eleven.

What do you think with the below Picture ?

Three people are in a room. Ronni looks at the Nile. The Nile looks at Senthil. Ronni is married but Senthil is not married. At any point, is a married person looking at an unmarried person? Yes, No or Cannot be determined.

Three ants are going up a hill, one behind the other. The last ant then says to the other ants, 'There is an ant behind me!'' How come?

Can you solve the maths in the below-given picture equation?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?