Math Puzzles 9

Puzzle 1: What number replaces the question mark?

1 + 1 = 8

2 + 2 = 32

3 + 3 = 72

4 + 4 = ?

Puzzle 2: What comes next in the sequence?

1 + 5 = 18

2 + 10 = 36

3 + 15 = 54

4 + 20 =?

Puzzle 3: What number replaces the question mark?

If 1 x 1 = 2

2 x 2 = 4

3 x 3 = 6

4 x 4 = 8

Then 4 x 1 =?

Puzzle 4: What number replaces the question mark?

Puzzle 5: What number replaces the question mark?

If 1 - 1 = 0

2 - 1 = 3

3 - 1 = 8

Then 5 - 1 =?