Neeraj purchased a few shirts for his shop at cost prices ranging from Rs. 400 to Rs. 550 and sold at prices ranging from Rs. 450 to Rs. 650. What is the maximum profit that might be made in selling 10 shirts?
A certain sum of money becomes double of itself in 15 years at a rate of simple interest. In how many years will it become 5 times of itself at the same rate of simple interest