Explanation:

Let's break down the problem:

- Let monthly salary = Rs. X

- Rent = 20% of X

- Remaining after rent = 80% of X

- Flight ticket = Rs. 5000

- Remaining = 0.8X - 5000

- Insurance : Savings = 3:2

- Amount for insurance = (3/5) × (0.8X - 5000)

- Amount for savings = (2/5) × (0.8X - 5000)

- Rent is Rs. 4000 less than insurance:

0.2X = (3/5) × (0.8X - 5000) - 4000

Let’s solve it:

0.2X + 4000 = (3/5) × (0.8X - 5000)

0.2X + 4000 = (2.4X - 15000)/5

0.2X + 4000 = 0.48X - 3000

4000 + 3000 = 0.48X - 0.2X

7000 = 0.28X

X = 7000 / 0.28

X = 25,000

- Option:1, Rs. 35000: Too high.

- Option:2, Rs. 45000: Too high.

- Option:3, Rs. 25000: Correct answer.

- Option:4, Rs. 20000: Too low.

- Option:5, Rs. 15000: Too low.

Correct answer is Option 3: Rs. 25,000.