question_answer

Two types of tea costing Rs. 180 per kg and Rs. 280 per kg should be mixed in the ratio so that the mixture obtained, sold at Rs. 320 per kg to earn a profit of 20% is     [SSC (CGL) Mains 2014]

A) 1: 13                

B) 2: 13

C) 3: 13                            

D) 4: 13

Correct Answer: B

Solution :

CP of the mixture \[=\frac{320}{120}\times 100=Rs.\frac{800}{3}\]

Now, according to the rule of mixture,

\[\therefore \] Required average \[=280-\frac{800}{3}:\frac{800}{3}-180\]

\[=\frac{40}{3}:\frac{260}{3}=2:13\]