By selling 30 articles, a shopkeeper gains the selling price of 9 articles. His gain percent is:
Answer & explanation
Correct answer: option 3
Let CP of the each article be Rs. x and SP of each article be Rs. y, then
30y – 30x = 9y
30y – 9y = 30x
21y = 30x
y : x = 30 : 21
CP = 21 and SP = 30
Profit = 30 – 21 = 9
Profit percentage = \(\frac{9}{21}\) × 100 = $42\frac{6}{7}$