Correct Answer - Option 4 : 50%
Given-
Decrease in Profit = 20%
Concept Used-
If a × b = constant, then a increase with the decrease in b.
Calculation-
Let initially the total sale be 100 and profit on sale of each article also be 100.
Total Profit = 100 × 100
Now, profit decreases by 20% i.e 80.
Total profit after 20% increase = 10000(1 + 20%)
⇒ 12000
Let sale now be x
According to Question-
12000 = x × 80
⇒ x = 150
⇒ Increase in sale = (150 - 100)/100 × 100
⇒ 50%