12 students would create 4 groups, if they get 8 cubic meters per hour and they have 5 hours, the equasion would look like: (8*5)*4)=160. They would clear 160 cubic meters in 5 hours.
Mean
: The average of all the data in a set.
Median
: The value in a set which is most close to the middle of a range.
Mode
: The value which occures most frequently in a data set.
12,9,12,11,10,18,7,19,13,19
Mean = 13 (Average)
Median = 12 (Middle)
Mode = 12, 19 (most common)
She reads at 55 pages per hour for 4 hours so 55*4 = 220 pages so far. This means that she read 220 and had 330 left so 220 + 330 = 550 so the book is 550 pages. If she reads 55 pages per hour and there is a total of 550 pages, 550/55 = 10 hours to read the book.