Question 12

The value of n is 3.

To solve the equation formed by the sum of n and the product 3 × n equaling 12, we set up the equation n + 3n = 12, which simplifies to 4n = 12. Dividing both sides by 4 gives us n = 3.

A) 2

Choosing 2 leads to the calculation 2 + 3 × 2, which equals 2 + 6 = 8. This does not satisfy the equation since 8 is not equal to 12, making option A incorrect.

B) 3

With n as 3, substituting into the equation gives us 3 + 3 × 3 = 3 + 9 = 12. This satisfies the original equation perfectly, confirming that option B is correct.

C) 4

If we take 4 as the value for n, we calculate 4 + 3 × 4, which equals 4 + 12 = 16. Since 16 does not equal 12, option C is also incorrect.

D) 4 ½

Substituting 4 ½ into the equation results in 4.5 + 3 × 4.5 = 4.5 + 13.5 = 18. This does not satisfy the condition of the equation, therefore option D is incorrect.

Conclusion

The correct answer is definitively n = 3, as it is the only option that satisfies the equation n + 3n = 12. All other options fail to meet the criteria set by the original problem, confirming that B is the only valid solution.