If the selling price of 30 toys is equal to the cost price of 50 toys, then find the gain percentage (round up to two decimal places).

Correct option is C

Given:

Selling price of 30 articles = cost price of 50 article 
Formula Used:
​$$\text{Profit \%} = \left( \frac{\text{Profit}}{\text{Cost Price}} \right) \times 100$$​​
Solution:
30SP = 50CP 

​$$\frac{SP}{CP}=\frac{5}{3}$$​​
Profit= $$\frac{(5-3)}{3}×100 \%$$ = 66.67%