Question

A person has a chemical of $Rs.$ $25$ per liter. In what ratio should water be mixed in the mixture so that by selling it at $Rs.$ $20$ per liter he may get a profit of $25$ $\%?$

• A. $14:9$
• B. $9:14$
• C. $16:9$
• D. $3:4$

Answer 1

The correct option is C $16:9$

Let us assume that he sells just one liter of the solution

cost of chemical = Rs. $25.$

selling price = Rs. $20.$

profit = $25$ %

$CP=SP\left(\frac{100}{100+P\%}\right)$

$=20\left(\frac{100}{100+25}\right)=\frac{20\times 100}{125}$

$=\frac{80}{5}=16$

For Rs. $25$, he can buy $1$ liter.

So, For Rs. $16$, he can buy $\frac{1\times 16}{25}l$

$=\frac{16\times 1000}{25}=640ml$

Hence the amount of water required $=360ml$.

Ratio $=640:360$

$=16:9$