Concept:Mean equals the sum of all numbers divided by the count of numbers.Explanation:Let the third number be x.Sum of the three numbers is 14+16+x=30+x.Number of numbers is 3.So, mean =330+x.Given mean =12, we have 330+x=12.Multiply both sides by 3: 30+x=36.Subtract 30 from both sides: x=6.Answer:The third number is 6 (Option A).