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
Step-by-step explanation:
Answer:
y = -1/3
Step-by-step explanation:
As x gets large, the value of the expression approaches the ratio of the highest-degree terms in numerator and denominator:
y = -3x^6/(9x^6) = -3/9
y = -1/3
Answer:
4
hours
Step-by-step explanation:
he was gone for 5 
hours, he spent 
an hour driving.
5 - = 4 hours at work.
