Question

The buying price of 5Kg of flour at Rs15 per Kg when 5% sales tax is added, will be
a.Rs. 68.75
b.Rs.78.75
c.Rs.88.75
d.None of these

Answer 1

Hint:In this question use the concept that the total price of the 5 Kg flour including sales tax will be equal to the addition of buying price of the 5 Kg flour and the 5% (buying price of the 5 Kg flour). This will help approaching the problem.

Complete step-by-step answer:
The buying price of the flour is Rs. 15 per kg.
So the buying price of 5Kg flour is the product of per Kg price and the total amount of the flour.
So the buying price of the 5 Kg flour = 5(15) = 75 Rs.
Now it is given that 5% sales tax is also added in the buying price.
So the total price of the 5 Kg flour including sales tax is the sum of the buying price of the 5 Kg flour and 5% of the buying price of the 5 Kg flour.
So construct a linear equation according to the above information we have,
So the total price of the 5 Kg flour including sales tax = buying price of the 5 Kg flour + 5% (buying price of the 5 Kg flour).
Therefore,
 So the total price of the 5 Kg flour including sales tax = Rs. 75 + $\dfrac{5}{{100}}$ (Rs. 75)
Now simplify this we have,
So the total price of the 5 Kg flour including sales tax = 75 + $\dfrac{1}{{20}} \times 75$
Now again simplify this we have,
So the total price of the 5 Kg flour including sales tax = $75 + 3.75 = $Rs. 78.75
So this is the required answer.
Hence option (B) is the correct answer.

Note:There is a difference between the price at which a good is being taken by the shopkeeper from another vendor and the price in which the consumer buys from the shopkeeper. The price at which the shopkeeper buys the product is termed as its cost price and price at which the shopkeeper sells the product to the consumer is termed as its selling price with respect to shopkeeper and buying price with respect to the consumer. Before applying the tax of 5% one must first find the total cost price for 5kg not just take the cost price for 1kg of flour.