A grocer purchased 200 kg of rice at Rs.25 per kg. He sold 80 kg of it at a gain of 10% and 40 kg at a loss of 4%. At what rate per kg should he sell the remainder to gain 8% on his total investment?

CP of Rice = 200 × 25

= Rs.5000

CP 0f 80 kg Rice = 80 × 25

= Rs.2000

SP of 80Kg rice sold at gain of 10%

= Rs.2200

CP of 40 kg Rice sold @4% loss = 40 × 25

= Rs.1000

SP of 40 Kg Rice sold @4% loss

= Rs.960

SP of Rice for Gaining 8% on total value

= Rs.5400

Total Wt. of Rice Sold = 80 + 40 = 120 Kg

Remaining Wt. of Rice to be Sold

= 200 - 120

= 80 Kg

Total amount obtained from Selling Rice

= 2200 + 960

= Rs.3160

Difference of Amount = 5400 – 3160

= Rs.2240

New Rate of Rice will be = Rs.2240 / 80

= Rs.28