Correct Answer - Option 4 : Neither I nor II

**Given: **

CP of table = T

CP of chair = C

T = C + 400

Profit on table = 15%

Profit on chair = 22%

Total gain = Rs. 615

**Formula Used: **

Profit = SP – CP

Profit% = (Profit /CP) × 100

SP = {(100 + P%)/100} × CP

Where P → Profit, CP → cost price and SP → selling price.

**Calculation:**

Profit on table = (15/100) × T

Profit on chair = (22/100) × C

Overall gain = Rs. 615

⇒ Profit on table + Profit on chair = 615

⇒ (15/100) × T + (22/100) × C = 615

Putting T = C + 400

⇒ (15/100) × (C + 400) + (22/100) × C = 615

⇒ (37/100) × C + 60 = 615

⇒ (37/100) × C = 555

⇒ C = 555 × 100/37

⇒ **C = 1500**

T = 1500 + 400

⇒ **T = 1900**

I. Average cost price of both is Rs. 1600

(1500 + 1900)/2 = 3400/2

⇒ 1700

⇒ I is incorrect

II. Selling price of chair is Rs. 1800

SP of chair = (100 + 22)/100 × 1500

⇒ 122 × 15

⇒ 1830

⇒ II is incorrect

**∴ ****Neither I nor II is correct.**