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About LinkBacksThere are 8 books, 6 of them are paperbacks and 2 of them are hardbacks. If 4 books are to be selected at random, in how many ways, there is at least 1 hardback book?
There are 8 books, 6 of them are paperbacks and 2 of them are hardbacks. If 4 books are to be selected at random, in how many ways, there is at least 1 hardback book?
6c3 * 2c1 + 6c2 * 2c2
6c3*2c1 + 6c2*1 = 55
8c4 - 6c4 = 55
Hey grey cellz. pl explain your response...
I get really confused with atleast in probability or combination Qs
8C4 is total ways in which you can select any 4 books out of 8
6C4 is the total ways you can select NO hardbacks
thus, total ways to select at least one hardback = 8C4 - 6C4
atleast one hardback book = 8C4 - No hardback book
8c4 - 6c4 = 70 - 15 =55
What you can do
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