A dealer sold $$\frac 56$$​th of his goods at 30 percent profit and the remaining at the cost price. What is his overall gain percent?

Correct option is B

Given:
A dealer sold $$\frac 56$$​ of his goods at 30% profit
The remaining $$\frac 16$$​was sold at the cost price
Formula Used:
​$$\text{Overall Gain \%} = \left( \frac{\text{Total Gain}}{\text{Total Cost Price}} \right) \times 100$$​​
Solution:
Let the total cost price be ₹6 
Cost of 5/6 goods = ₹5
Profit on ₹5 = 30% of 5 = ₹1.5
Selling price for 5/6 goods = ₹5 + ₹1.5 = ₹6.5
Cost of remaining 1/6 goods = ₹1
Sold at cost price → Selling price = ₹1
Total Cost Price = ₹6
Total Selling Price = ₹6.5 + ₹1 = ₹7.5
Total Gain = ₹7.5 − ₹6 = ₹1.5
Overall Gain % = $$\frac{1.5} 6$$​× 100 = 25%