Shortcut Trick
Assume the total area is 100 units. CP = 3,00,000.
Total profit needed = 15% of 100 = +15 units.
Part 1: 25% area at 25% loss ⇒ 25 × (−0.25) = −6.25 units.
Part 2: 40% area at 25% profit ⇒ 40 × 0.25 = +10 units.
Current net profit = −6.25 + 10 = +3.75 units. Remaining profit needed = 15 − 3.75 = 11.25 units.
Remaining area = 100 − 25 − 40 = 35%. SP of remaining part = CP of remaining + profit needed = (35% of 3,00,000) + (11.25% of 3,00,000).
SP of remaining = (46.25 ÷ 100) × 3,00,000 = 1,38,750.
∴ The correct answer is ₹ 1,38,750.
Alternate Method
Given → Total CP = 3,00,000 | Overall Profit = 15% | Plot divided into 25%, 40%, and 35%.
Formulas: SP = CP × (100 + P%) ÷ 100 | Profit = SP − CP.
⇒ Total SP required = 3,00,000 × 1.15 = 3,45,000.
⇒ SP1 (25% area) = (0.25 × 3,00,000) × 0.75 = 75,000 × 0.75 = 56,250.
⇒ SP2 (40% area) = (0.40 × 3,00,000) × 1.25 = 1,20,000 × 1.25 = 1,50,000.
⇒ Sum of SP1 and SP2 = 56,250 + 1,50,000 = 2,06,250.
⇒ SP of remaining plot = Total SP − (SP1 + SP2) = 3,45,000 − 2,06,250 = 1,38,750.
∴ The correct answer is ₹ 1,38,750.
Additional Information
Weighted Average Method
For problems involving parts of a whole, use (w1p1 + w2p2 + w3p3) = WtotalPtotal where w is the weight and p is the profit/loss percentage.
Profit and Loss on Cost Price
Unless stated otherwise, profit or loss percentage is always calculated on the Cost Price (CP).