Here number of winners and prize money are in inverse proportion because winners are increasing, prize money is decreasing.
When the number of winners are 4, each winner will get = 100000/4 = ₹25,000
When the number of winners are 5, each winner will get = 100000/5 = ₹20,000
When the number of winners are 8, each winner will get = 100000/8 = ₹12,500
When the number of winners are 10, each winner will get = 100000/10 = ₹10,000
When the number of winners are 20, each winner will get = 100000/20 = ₹5,000