Hint: In this question, we will first substitute all the alphabet symbols with the mathematical operation they represent and then apply the BODMAS rule to solve it.
Complete step-by-step answer:
Here, in given question, English alphabets are used as a symbol in place of mathematical operations as given below:
L represents addition, that is $+$,
M represents subtraction, that is $-$,
N represents multiplication, that is $\times $,
P represents division, that is $\div $.
For example, 2 L 3 will mean 2 + 3.
Also, according to the BODMAS rule, while evaluating any given expression in mathematics, order of preference is: Bracket, Of, Division, Multiplication, Addition, Subtraction.
Now, the given expression is,
14 N 10 L 42 P 2 M 80
Changing alphabets to mathematical operations, we get,
\[14\times 10+42\div 2-80\]
Using BODMAS rule, we will first do division, so dividing 42 by 2, we get,
Second operation here according to BODMAS rule is multiplication, so multiplying 14 by 10, we get,
third operation here according to BODMAS rule is addition, so adding 140 with 21, we get,
Now subtracting 161 by 80, we get,
Hence, the value of the given expression is 81.
Therefore, the correct answer is option (b).
Note: In this type of questions, do not get confused by the alphabets between the numbers in an expression, it is just a BODMAS rule problem and alphabets are added to check your aptitude knowledge.