Correct Answer - Option 4 : 61.2%
Given:
Mixture of Whiskey and Water = 340 liter
Percentage of water = Z%
The shopkeeper sold of the mixture = 40 liter
Percentage of Whiskey in final mixture = 54%
Calculation:
Whiskey = 340 × (100 – Z)/100
40 liters replaced then,
⇒ 340 × (100 – Z)/100 – 40 × (100 – Z)/100 = 54% of 340
⇒ [(100 – Z)/100][340 – 40] = (54/100) × 340
⇒ [(100 – Z)/100] × 300 = 183.6
⇒ 300 – 3Z = 183.6
⇒ 3Z = 116.4
⇒ Z = 38.8%
⇒ Initial Whiskey = 100 – 38.8
⇒ 61.2%