Find mean, median and mode of 140, 130, 90, 80, 60, 50, 30, 20, 10, 0

For the mean you would add up all the values and divide by how many numbers there are. For this problem, you would get 610/10=61.

For the median you would arrange all the numbers from least to greatest and cancel one from the left and one from the right until you get to the middle. In this case 50+60 =110 and then you divide by 2 =55.

For the mode there is no mode because none of the numbers repeat. 

I hope this clarifies your doubts. :)