8*8 = 64 squares
first piece has two possible spots
so
2/64 is chance it will pick one of them
now there are 63 spots left and the second piece has to hit it.
1/63 is that probability
2/64 * 1/63 = 4.96*10^-4 = .000496
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8 rows
first piece can hit any row but leaves that row with 7 empty spaces
second piece 7/63 chance that it hits that row
so 7/63
A chessboard has 8 rows and 8 columns. A rook and a bishop are put randomly and with equal probability among all pairs of squares of the board.
a. What is the probability that the two pieces are put on the squares (1,1) and (1,2)?
b. What is the probability that the two pieces are put on the same row?
1 answer
1 answer