Puzzles - Number puzzles

271.
Answer
:
5
Explanation
:
In each column of the diagram, the central value equals the average of the upper and lower numbers.

272.
Answer
:
14
Explanation
:
In each star, the central value equals the sum of the top and lower two numbers, minus the left and right hand numbers.

273.
Answer
:
1
Explanation
:
Read each row of 3 numbers as a 3 digit number, and add the top row value to the middle row, to give the result written in the bottom row.