Plz solve the attached image, Ans: c

Asked by vishakhachandan026 | 25th Jun, 2019, 07:02: AM

Expert Answer:

Let X be the number of mines in the first two columns.
Let Y,Z,W,V be the number of mines in the third, fourth, fifth, and sixth columns, respectively.
We need to have X + Y = 2,
Y + Z + W = 1, and
W + V = 2.
This can happen in three ways, which are (X,Y,Z,W,V) = (2, 0, 1, 0, 2),(2, 0, 0, 1, 1),(1, 1, 0, 0, 2).
consider
(2, 0, 1, 0, 2)
to place 2 in columns that denote X we have 5 places 5C2 = 10 ways
to place 1 in column of Z we have 2 places = 2C= 2 ways
also to place 2 in column of V we have 2 places = 2C= 1 way
similarly for (2, 0, 0, 1, 1) and (1, 1, 0, 0, 2)
 
This gives (10)(2)(1) + (10)(3)(2) + (5)(3)(1) = 95 possible configurations

Answered by Arun | 9th Jul, 2019, 09:52: AM

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