Easy
Find the missing number in the grid: Row1: 1, 5, 9 | Row2: 4, 8, 12 | Row3: 7, ?, 15
Explanation
Explanation
Look at each column: Column 1 is 1, 4, 7 (adding 3 each row). Column 2 is 5, 8, ? (adding 3 each row, so the missing number is 11). Column 3 is 9, 12, 15 (adding 3 each row), confirming the pattern.
PRO TIP
Re-check your working by substituting the answer back into the original question.