A trader mixes 80 kg of tea at 15 per kg with 20 kg of tea at cost price of 20 per kg. In order to earn a profit of 40%, what should be the sale price of the mixed tea?  Choose the correct choice from the following choices.
A) 22.4  B) 22  C) 20  D) 19.2  E) none of these

Rationale: c . p . of mixture = 80 × 15 + 20 × 20 / 80 + 20 = 16 ∴ s . p . = ( 100 + 40 ) / 100 × 16 = 22.4 answer a
Answer: A