Final answer:
To find the gain percent, we need to calculate the cost price and the selling price. Given that the grocer sells 40 litres of oil for the cost price of 42 litres, we can calculate the gain percent using the formula (Selling Price - Cost Price) / Cost Price x 100. The grocer's gain percent is 0%.
Step-by-step explanation:
To find the gain percent, we first need to calculate the cost price and the selling price.
Given that the grocer sells 40 litres of oil for the cost price of 42 litres, we can calculate the cost price per litre by dividing the total cost by the total quantity.
Cost price per litre = Cost Price / Total Quantity = 42 liters / 40 liters = 1.05
Since the selling price is the same as the cost price in this case, the selling price per litre is also 1.05.
The gain percent is calculated as:
Gain Percent = (Selling Price - Cost Price) / Cost Price x 100
Gain Percent = (1.05 - 1.05) / 1.05 x 100 = 0%
Therefore, the grocer's gain percent is 0%.