Question

How many quarts of pure antifreeze must be added to 9 quarts of a 10​% antifreeze solution to obtain a 30​% antifreeze​ solution?

Answer 1

Answer: 2.6 quarts

Step-by-step explanation:

According to ratio and proportion:

where,

`C_1` = concentration of first solution = 10 %

`m_1` = mass of first solution = 9 quarts

`C_2` = concentration of pure solution = 100%

`m_2` = mass of pure solution = x quarts

`C_3` = concentration of final solution = 30 %

`m_3` = mass of final solution = (9+x) quarts

`10* 9+100* x=30* (9+x)`

`x=2.6quarts`

Thus 2.6 quarts must be added to 9 quarts of a 10​% antifreeze solution to obtain a 30​% antifreeze​ solution.