What is common among 11, 69, and 88?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

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?

No matter how little or how much you use me, you change me every month. What am I?

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

In which direction should the missing arrow point?

I am sure no one can have two things for dinner. what are they?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"