A shopkeeper allows a discount of 10% on an article marked at Rs. 800. What is the selling price? MCQ with Answer and Explanation

Explanation:
Total CP = 100*10 = 1000. SP = 80*12 + 20*8 = 960 + 160 = 1120. Profit = 120, profit% = 12%? Wait 120/1000*100=12%, not in options. Let's check: actually 80*12=960, 20*8=160, total SP=1120, CP=1000, profit=120, profit%=12%. But option A says 4%. That's wrong. Let's recalc: maybe he sells 80 at Rs.12 each (960) and remaining 20 at Rs.8 each (160) total 1120, profit 120, 12%. Not in options. So this question is flawed. Delete and regenerate.

Explanation:
When CP is the same for two articles, and one is sold at x% profit and the other at x% loss, the overall result is No Profit No Loss.

Explanation:
Let CP of 1 = 1, CP of 10 = 10, SP of 9 = 10 => SP of 1 = 10/9 = 1.111, gain = 11.11%.