Since this is a combination not a permutation problem, (order does not matter) you should use the "n choose k" formula.
C=n!/(k!(n-k)!) where C is the number of unique combinations, n equals the total number of possible choices and k equals the specific number of choices. In this case:
C=9!/(4!(9-4)!)
C=9!/(4!5!)
C=362880/(24*120)
C=362880/2880
C=126
So there are 126 unique ways to pick 4 people from a group of 9 people.
D.8
A and C are out because they would get you ether lower or equal to 20, which is equal to AC and your trying to find X in AB which is so posed to be the what equals AC+BC.
AB=AC+BC
5x=20+BC
5(8)=20+BC
40=20+BC
40=20+20
AC equals 20. AB will have to equal AC+ CB. If you put in A.4 in AB 5X you will get twenty and that not what you want. You want to get a number that will get you the an answer greater to AC. So 5(8)=40.
They would have used a total of 30 horses. Each person would've each ridden 15 so 15+15= 30 and 165 divided by 11 is 15. Hope this is off help!
Shyam travel total 
distance ,when he travelled 
by bus and 
by car .
How to find the total distance travel by Shyam ?
Shyam travelled distance by bus 
Shyam travelled distance by car 
Total distance travelled by shyam is
Total distance= distance travelled by car + distance travelled by bus
Total distance
Learn more about the distance travel is here :
brainly.com/question/28048546
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Answer:It doesn't make sense when I try to do it,I even tried a calculator
Step-by-step explanation: IDK?
