Question

A trader buys one variety of coffee at Rs. 30 per kg, and another variety of coffee at Rs. 40 per kg. He mixes them together in some proportion and when he sells the mixture at Rs. 36 per kg, he realizes that he is making a profit of 12.5% over his cost price. What percentage of the mixture is the cheaper coffee?

Answer 1

I guess it is not the correct answer 1245367890123456789009875

Answer 2

Answer: 80% of the mixture is the cheaper coffee.

Step-by-step explanation:

Since we have given that

Price of one variety of coffee = Rs. 30 per kg

Price of another variety of coffee = Rs. 40 per kg

Selling price of the mixture = Rs. 36 per kg

At which he earns profit of 12.5%.

So, Cost price of the mixture is given by

$\frac{100+12.5}{100}\times x=36\\\\\frac{112.5}{100}\times x=36\\\\x=\frac{100}{112.5}\times 36\\\\x=Rs.32$

Now, we will use "Mixture Allegations":

         Cheaper        Dearer

             30                40

                        32

-----------------------------------------------

     (40-32)         :     (32-30)

        8                :        2

         4               :         1

So, we need to find the percentage of the mixture is the cheaper coffee is given by

$\frac{4}{5}\times 100\\\\=80\%$

Hence, 80% of the mixture is the cheaper coffee.