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 25%, what should be the sale price of the mixed tea?	Choose the most appropriate option.
A) 23.75  B) 22  C) 20  D) 19.20  E) none of these

Rationale: "c . p . of mixture = 80 × 15 + 20 × 20 / 80 + 20 = 16 ∴ s . p . = ( 100 + 25 ) / 100 × 16 = 20 answer c"
Answer: C