Puzzles - Number puzzles

262.
Answer
:
12
Explanation
:
Working from the bottom row to the apex of the triangle, the sum of the values in each row follows the sequence 15, 14, 13,12.

263.
Answer
:
6
Explanation
:
Each row and column of the diagram adds up to 15.

264.
Answer
:
A:319 B:424
Explanation
:
In the first oval, the sum of the separate digits of each 3 digit number is 9, and in the second oval, the sum of the separate digits is 7.