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:
the first problem is 216cm
Step-by-step explanation:
(first problem) The 8cm is pointless it just give extra unneeded info a little trick my techer taught me is when you dealing with parellelagrms what you should do is see the dotted line well move the shape the is on the left side of the dotted line to the right side of the parrallelagram and now its a rectangle so all you need to do is 9cm x 24cm = 216cm
I dont think i can help with the secound one sorry but does this help?
The answer is in the question itself... so since it says 20 miles per hour that’s the distance it covers per hour. the answer would be it travels 20 miles in an hour
Answer:70
Step-by-step explanation:
