Question

A shop keeper sells 3/4th of its article at a gain of 20% and the remaining at cost price. Find his real gain %​

Answer 1

Answer:

No I can’t, because I lack at least one of the prices. But I can give you his net profit rate.

Let

C be the cost of one article

n be the number of articles

G being the gross sum he earned

P be the net profit

R be the net profit rate

From the problem, we know that

G=34nC×(1+20100)+14nC

In other terms

G=n4(3C×120100+C)=nC4460100=nC115100

Then, the profit being the gross earned sum minus the initial cost

P=nC115100−nC=nC15100

As you see, to answer your question, I would need to be able to evaluate nC , an element I don’t have. But now, the net profit rate is the ratio between the net profit and the initial cost. So

R=PnC=nC15100nC=15100

His net profit rate was

15%