Suraj bought 90 articles at ₹12.50 per article. He sold 60% of them at ₹15 per article and 50% of the remaining at ₹10.50 per article. At what price (in ₹) per article should he sell the remaining articles to get 20% profit in the entire transaction?

Total number of articles = 90
Cost Price (CP) per article = ₹12.50
Total CP=90×12.50=₹1125

To get a 20% profit on the entire transaction, the required total Selling Price (SP) is:

Total SP=1125×1.20=₹1350
Let's break down the sales:

60% of the articles:

Number of articles=60% of 90=54
SP
1
​
=54×15=₹810
Remaining articles after the first sale =90−54=36
50% of the remaining articles:

Number of articles=50% of 36=18
SP
2
​
=18×10.50=₹189
Articles left for the final sale =36−18=18

Let the required selling price per article for the remaining articles be x.

Total SP=SP
1
​
+SP
2
​
+(18×x)
1350=810+189+18x
1350=999+18x
18x=1350−999
18x=351
x=
18
351
​
=19.5
Thus, he should sell the remaining articles at ₹19.5 per article.