How many words can a pen with half refill write?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?

During an interview, the interviewer ordered hot coffee for the candidate to relieve the stress. The coffee was kept before him. After a minute, the interviewer asked him, 'What is before you?' He replied 'Tea'.

The candidate was selected immediately. Why?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

Before Mount Everest was discovered, what was the highest mountain in the world?

There is a rock group of four men that do not sing. Name It?

There is something which is always coming but never arrives?

The day before yesterday I was 25 and the next year I will be 28. This is true only one day in a year. What day is my birthday?

You need to cut a round cake into eight equal pieces with just 3 cuts. Can you do it?

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?