We must find UNIQUE combinations because choosing a,b,c,d... is the same as d,c,b,a...etc. For this type of problem you use the "n choose k" formula...
n!/(k!(n-k)!), n=total number of choices available, k=number of choices made..
In this case:
20!/(10!(20-10)!)
20!/(10!*10!)
184756
Answer:
B) Subtract 12-4 to calculate the range of this data set
If this is asking for the nearest hundred thousand, and not ten thousand, than you would round up to 100,000. 91,284 is close to 100,000.
To find the number of minuets you spent playing your game and reading you would solve this equation
35+(8x4)