A mptprbpat travels downstream on a river for five hours. The speed of the current is 2km/h. The river flows into a still lake and the motoboat continues for two more hours. The distance covered by the boat on the river was 40km more than the distance it covered on the lake. Whatis the speed of the motorboat in still water?

Lisa has three classes that each last 50 minutes. what is the total number of minutes of the three classes

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Acompany manufactures three types of cabinets. it makes 110 cabinets each week. in the first week, the sum of the number of type-1 cabinets and twice the number of type-2 cabinets produced was 10 more than the number of type-3 cabinets produced. the next week, the number of type-1 cabinets produced was three times more than in the first week, no type-2 cabinets were produced, and the number of type-3 cabinets produced was the same as in the previous week.