If "L" stands for "+", "M" stands for "−", "N" stands for "×" and "P" stands for "÷", then what is the numerical value of the coded expression 14 N 10 L 42 P 2 M 8 ?

Introduction / Context:
This coded arithmetic problem assigns letters to ordinary operators: addition, subtraction, multiplication and division. By decoding each symbol and applying the usual order of operations, we can determine the value of the expression. Such questions reinforce discipline in handling coded notation and arithmetic precedence, both of which are crucial in many reasoning exams.

Given Data / Assumptions:

• L stands for plus (+).
• M stands for minus (−).
• N stands for multiplied by (×).
• P stands for divided by (÷).
• The coded expression is 14 N 10 L 42 P 2 M 8.
• We use standard arithmetic precedence: perform multiplication and division before addition and subtraction.

Concept / Approach:
First, we translate the expression from its letter-based code into a normal arithmetic expression. Then we evaluate the result step by step, ensuring strict adherence to operator precedence. Multiplications and divisions are evaluated first from left to right, followed by addition and subtraction from left to right, to arrive at the final numeric value.

Step-by-Step Solution:
Step 1: Replace each coded symbol with its arithmetic operator. Step 2: 14 N 10 L 42 P 2 M 8 becomes 14 × 10 + 42 ÷ 2 − 8. Step 3: Evaluate the multiplication: 14 × 10 = 140. Step 4: Evaluate the division: 42 ÷ 2 = 21. Step 5: Substitute these results back into the expression to get 140 + 21 − 8. Step 6: Perform the addition: 140 + 21 = 161. Step 7: Now subtract 8: 161 − 8 = 153. Step 8: Thus, the value of the coded expression is 153.

Verification / Alternative check:
We can verify quickly by doing the computation again in a slightly different grouping. After decoding, the expression is 14 × 10 + 42 ÷ 2 − 8. Compute 14 × 10 to get 140, compute 42 ÷ 2 to get 21, and combine them as 140 + 21 = 161. Subtract 8 to reach 153. Both paths agree, ensuring that no arithmetic mistake has been made.

Why Other Options Are Wrong:
Option 216 would correspond to miscomputing 42 ÷ 2 or adding instead of subtracting 8. Options 248 and 251 require even more significant deviations from correct arithmetic or ignoring the division step. Because the intermediate steps yield simple integers and the operations are basic, any number other than 153 signals a clear error in decoding or calculation.

Common Pitfalls:
Errors often come from rushing and either mixing up which letter stands for which operator or applying addition and subtraction before finishing multiplication and division. Misreading P as plus or L as division, for example, will completely change the result. Taking the time to rewrite the full decoded expression before calculating helps prevent these confusions.

Final Answer:
Interpreting L, M, N and P as +, −, × and ÷ respectively, the coded expression 14 N 10 L 42 P 2 M 8 evaluates to 153.