Answer: (A) Rs 150
Explanation: Let Cost Price = Rs 100, Selling Price = Rs 120
If Cost Price = Rs 40
Profit = 50%, hence Selling Price = (40 * 150)/100 = Rs 60
Difference of Selling Price = (120 – 60) = Rs 60
When difference is Rs 60, Cost Price = 100
When difference is 90, Cost Price = Rs 150