Puzzles - Number puzzles

154.
Answer
:
2
Explanation
:
Reading each row as a whole number, multiply the top 2 digit number by the lower 2 digit number to give the result represented by the middle 3 digit number.

155.
Answer
:
13
Explanation
:
Starting with the top circles, multiply each value by 2 and subtract 3, writing the result in the corresponding segment of the lower circle.

156.
Answer
:
6
Explanation
:
Numbers in boxes from the second row up equal the average of the 2 numbers in the boxes directly below. Continue to the apex of the triangle.