• question_answer A grocer buys 80 kg of rice at Rs. 13.50 per kg and mixes it with 120 kg of rice available at Rs. 16 per kg. At what rate per kg should he sell the mixture to gain 20% on the whole? A)  18     B)  16            C)  20                               D)  22

(a): Total $C.P=80\times 13.5+120\times 16$ = 1080+1920 = 3000/- $20%\text{ }gain\Rightarrow 3000\times 1.2=3600/-$ $\therefore Total\text{ }rice=\left( 80+120 \right)kg=200kg$ $\therefore \text{S}.P=\frac{3600/-}{200}Rs/kg=18Rs/kg.$