$$10\div(10+15)=40\textbackslash\%$$. 
A sugar solution is made by mixing $$10$$ ounces of sugar and $$15$$ ounces of water. Find the percent concentration of the solution. 
Options:
a. $$20\textbackslash\%$$ 
b. $25\textbackslash\%$ 
c. $30\textbackslash\%$ 
d. $40\textbackslash\%$ 