The average of the monthly salaries of M, N and S is ₹ 4000. The average of the monthly salaries of N, S and P is ₹ 5000. The monthly salary of P is ₹ 6000. What is the monthly salary of M as a percentage of the monthly salary of P?

The correct option is 50%.

Let the monthly salaries of M, N, S, and P be represented by $M$, $N$, $S$, and $P$ respectively.

Step 1: Write down the equations based on the given averages.
The average of the monthly salaries of M, N, and S is ₹ 4000.
Therefore, the sum of their salaries is:
$\frac{M+N+S}{3}=4000$
Multiplying both sides by 3, we get:
$M+N+S=12000$     — (Equation 1)

The average of the monthly salaries of N, S, and P is ₹ 5000.
Therefore, the sum of their salaries is:
$\frac{N+S+P}{3}=5000$
Multiplying both sides by 3, we get:
$N+S+P=15000$     — (Equation 2)

Step 2: Find the sum of salaries of N and S.
We are given that the monthly salary of P is ₹ 6000 ($P=6000$).
Substitute the value of $P$ into Equation 2:
$N+S+6000=15000$
Subtracting 6000 from both sides gives:
$N+S=9000$     — (Equation 3)

Step 3: Calculate the salary of M.
Substitute the value of $N+S$ from Equation 3 into Equation 1:
$M+9000=12000$
Subtracting 9000 from both sides gives:
$M=3000$

Step 4: Find the monthly salary of M as a percentage of the monthly salary of P.
The required percentage is calculated as:
$\text{Percentage}=\left(\frac{M}{P}\right)\times 100$
Substituting the values of $M=3000$ and $P=6000$:
$\text{Percentage}=\left(\frac{3000}{6000}\right)\times 100$
Simplifying the fraction:
$\text{Percentage}=\frac{1}{2}\times 100=50\%$