What does this rebus means ?

PROG WORKRESS

Why Aeroplane windows are round?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

I have an apple tree , number of apple in this tree get doubles every week.

On 30th week , the tree gets completely filled with apples :-)



Can you tell me , on what week does my tree is half covered with apples ?

What three numbers, none of which is zero, give the same result whether they’re added or multiplied?

I am working in a bus company. The company recently went under expansion and therefore there was not enough room for all the buses. As a result, twelve buses had to be stored outside.

If the company decides to expand the garage space by forty percent, enough space to accommodate the current buses will be created leaving enough space for twelve more buses if the need arises in future.

Can you calculate the number of buses that the company owns at present?

What month of the year has 28 days?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

What English word has three consecutive double letters?

It has a long neck, A name of a bird, Feeds on cargo of ships, It's not alive,

What is it?