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?

If dog can walk from A to B in 55 minutes, while mouse can walk from B to A in 66 minutes. If both start walking at same time, after what time will they cross each other?

The graph shows the temperature forecast and the actual temperature of a city on ten days. Find the maximum deviation of actual temperature from the forecast.

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?