Question

A trader buys one variety of coffee at 30 per kg and another variety of coffee at 40 pe kg .he mixes them together in some proportion and when he sells the mixture at 36 per kg he realises that he is making a profit of 12.5per over his cost price.what percentage of the mixture is the cheaper coffee

Answer 1

The percentage of cheap coffee in the mixture will be 80%

Explanation :

Percentage profit by selling the mixture at Rs 36 = 12.5%

Hence cost price of the mixture per kg = 36 x 100/112.5

= Rs 32 per kg

Let x be the amount of cheaper coffee(30/kg) in 1 kg, so amount of expensive coffee = 1-x

Hence cost price of the mixture;

=> 30x + 40(1-x) = 32

=> 30x + 40 - 40x = 32

=> 10x = 8

=> x = 0.8 = 80%

Hence the percentage of cheap coffee in the mixture will be 80%