What does the below rebus riddle means?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

You are playing a game with your friend Jack. There are digits from 1 to 9. You both will take turn erasing one digit and adding it to your score. The first one to score 15 points will win the game.

Would you want to play first or second?

PS: The sum should be exactly 15.

Which is the correct shadow of the bird?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

Can you count the number of squares in the figure below?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

Can you complete the sequence?

192, 021, 222, 324, 252, 627, 2__, 9__?

Can you name an animal whose killing cannot be performed without spilling your own blood?