how many ways to combine five things three at a time?
n!/[r!(n-r)!]
5!/[3!(2!)]
5*4/2
10
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4 along each long side with no ends
5 along each short side including end posts
9*2 = 18
Mimo wishes to leave a waitress a tip. Mimo has five coins in his pocket, a penny, a nickel, a dime, a quarter, and a half-dollar. If he uses exactly three coins for the tip, how many different tips are possible?
A. 15
B. 5
C. 20
D. 10
Crystal wants to put a fence around her vegetable garden.Her garden is 5 ft wide and 4 ft long.She plans to put a post at each corner and at every foot.How many fence posts will Crystal need? (1 point)
14 posts
18 posts
19 posts
20 posts
2 answers
thank you