A shopkeeper sells two qualities of rice at the rates of BD22 per kg. and BD18 per kg, gaining 10% and 20% profit respectively. If he mixes the two variants in the ratio 4:1 and sells the mixture at BD16.15 per kg., what is his gain or loss?
You are given a number N with the property that every next digit of N is greater than the previous digit (so second digit from the left is greater than the first digit, and third digit is greater than the second and so on). Now multiply N by 9. What is the sum of the digits of the resulting number?