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:
C
Step-by-step explanation:
Y= 4^2 - 5 x 4 + 4 = 0
Answer:
x = 6
Step-by-step explanation:
When 2 chords of a circle intersect then the product of the parts of one is equal to the product of the parts of the other, that is
2x = 3 × 4, that is
2x = 12 ( divide both sides by 2 )
x = 6
768.57 / 41.1 = 18.7 m per hr