You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

What Does this text mean:

important=important

During a secret mission, an agent gave the following code to the higher authorities
AIM DUE OAT TIE MOD

However, the information is in one word only and the rest are fake. To assist the authorities in understanding better, he also sent them a clue, If I tell you any one character of the code, you can easily find out the number of vowels in the codeword.

Can you find out the code word?

Count the number of triangles in the below picture?

I had an infinite supply of water and 5 litres and 3 litres jars.

How would you measure exactly 4 litres in the least number of steps?

I went to the bookshop and spent one-half of the money that was in my purse.

When I came out, I found that I had as many cents as I had dollars and half as many dollars as I had cents when I went in. Find the money in my purse when I entered the store.

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?