07 June 2014
7 distinct things are to be divided in 3 groups ,consisting of 2,2 and 3 things respectively,number of waus this can be done is equal to
a. 110
b. 105
c. 100
d. none
we know that there are n choices for the first selection. Whatever selection is first made, there will be n − 1 remaining items to choose from. Thus, the second choice can be made in n − 1 different ways, and the first two choices occur in n(n − 1) ways. Similarly,for the third choice we are left with n − 2 unselected items, so the third choice can be made in n − 2 different ways. Hence the first three choices can occur in n(n − 1)(n − 2) distinct ways. . . What is the answer?-Hope i am correct
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