The cost of a washing machine is 25% less than the cost of a TV.

Let the cost of a TV = ₹100 (for simplicity)
Then, cost of a washing machine = 25% less than TV
Cost of washing machine = 100 - 25 = 75

Step 1: Total cost before changes

4 washing machines + 5 TVs:

$ 4 \cdot 75 + 5 \cdot 100 = 300 + 500 = 800 $

Step 2: New costs after changes

• Washing machine increases by 87% → New cost = $ 75 \cdot 1.87 = 140.25 $

• TV decreases by 45% → New cost = $ 100 \cdot 0.55 = 55 $

Total new cost:

$ 4 \cdot 140.25 + 5 \cdot 55 = 561 + 275 = 836 $

Step 3: Percentage change in total cost

$ \text{Percentage change} = \frac{836 - 800}{800} \times 100 = \frac{36}{800} \times 100 = 4.5% $

✅ Answer: 4.5% increase