Question

A person bought some articles at the rate of 5 per rupee and the same number at the rate of 4 per rupee. He mixed both the types and sold at the rate of 9 for 2 rupees. In this business he suffered a loss of Rs. 3. The total number of articles bought by him was `540` b. `545` c. `1080` d. `1090`

Answer 1

L.C.M 0f 4,5 and 9=180
Cost price of 360 articles(180 articles each of both type)= `180xx1/5+180xx1/4=36+45=Rs.81`
Selling price for 360 articles=`360xx2/9=Rs.80`
Loss=`Rs.81-80=Rs.1`
now given he suffers a loss of 3 rupees.
now Rs.. 1 is lost for 360 articles therefore by unitary method for Rs.3 is lost for 1080 articles.