Answer : Option C

Explanation :

Solution 1:

Let the cost price = 100
The owner sells the phone on the price 23% more than the cost price.
So, the selling price is 100+23 = 123.
ATQ, the customer has to pay 7011 to purchase the cell phone.

If the selling price is 123 the cost price is 100.
If the selling price is 1 the cost price is 100/123.
If the selling price is 7011, the cost price =(100/123) * 7011
= 5700

Solution 2:

Let a number x to compare the assumed selling price and actual selling price.
i.e., 123 * x =7011
x = 57

That means if we multiply the assumed value with 57, we get the original selling price.
So, multiply the cost price with 57 to get the original cost price, i.e., 100 * 57 = 5700.