Can you replace the question mark with the correct number in the below table sequence?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

Solve the maths equation in the picture below by placing the numbers 1 through 9 into the boxes so that all the 3 equations are correct.

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

John left on a horse on Thursday , was gone for two days, and came back on Thursday after completing his work. How did that happen?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

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

What word is represented by this rebus?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?