Answer: B) Rs.17,500 Explanation: Let’s assume John bought the laptop for Rs. 100He then sells it to Mark at a loss of 20% => Rs. 80,Who consequently sells it to Kevin at a profit of 25% =>  Rs. 100Then, Kevin sells it back to Mark for Rs. 90 (Rs.4.50 for every Rs. 5 that he had paid initially), so he suffers a loss of Rs. 10Therefore, for Rs. 100 there is a loss of Rs. 10,Then for Rs. 1,75,000 there will be a loss of Rs. 17,500.

Answer: A) 1 Explanation: Only one such symbol is there in the given arrangement. It is 4@5.