Let the amount spent by Ashish is a, Banti is b and Chintu is c. Given, a=b=c One of them has bought a large bag. So, he must have spent at least 1000‌rupees It means, everyone has spent at least 1000 Or, a+b+c≥3000. Revenue from small bags =50×15=750. Revenue from large bag =1000×1=1000. Total revenue excluding from medium bag =750+1000=1750 If 4 medium bags are sold, total revenue =200×4+1750=2550, which is less than 3000 Hence, not the right answer. If 5 medium bags are sold, total revenue =200×5+1750=2750, which is less than 3000. Hence, not the right answer. If 7 medium bags are sold, total revenue =200×7+1750=3150, which is more than 3000. Hence, 7 is the correct answer.