If a rook and a bishop of a standard chess set are randomly
placed on a chessboard, what is the probability that one is
attacking the other?
Note that both are different colored pieces.
Answer Posted / guest
The probability of either the Rook or the Bishop attacking
the other is 0.3611
A Rook and a Bishop on a standard chess-board can be
arranged in 64P2 = 64*63 = 4032 ways
Now, there are 2 cases - Rook attacking Bishop and Bishop
attacking Rook. Note that the Rook and the Bishop never
attack each other simultaneously. Let's consider both the
cases one by one.
Case I - Rook attacking Bishop
The Rook can be placed in any of the given 64 positions and
it always attacks 14 positions. Hence, total possible ways
of the Rook attacking the Bishop = 64*14 = 896 ways
Case II - Bishop attacking Rook
View the chess-board as a 4 co-centric hollow squares with
the outermost square with side 8 units and the innermost
square with side 2 units.
If the bishop is in one of the outer 28 squares, then it can
attack 7 positions. If the bishop is in one of the 20
squares at next inner-level, then it can attack 9 positions.
Similarly if the bishop is in one of the 12 squares at next
inner-level, then it can attack 11 positions. And if the
bishop is in one of the 4 squares at next inner-level (the
innermost level), then it can attack 13 positions.
Hence, total possible ways of the Bishop attacking the Rook
= 28*7 + 20*9 + 12*11 + 4*13
= 560 ways
Thus, the required probability is
= (896 + 560) / 4032
= 13/36
= 0.3611
| Is This Answer Correct ? | 7 Yes | 2 No |
Post New Answer View All Answers
There is puzzle with the word "CONSTANTINE" and exactly don't know the question if anybody knows the Q&A plz send it ahmed.basha.munna@gmail.com
what job position/s are you currently holding with your current employer?
Wo kay chej hi jo saal may 1 baar aata hai months may 2 baar aata hai weeks may 4 baar aata hai or din may 6 baar
sir i need generalKnowledge previous questions for rrb secunderabad goods guard exam
Ship is 180 miles away from shore. At that time a plane started from shore to pass some information to the ship with 10 times velocity of ship's velocity. At what distance from shore they will meat?
how soon can you travel down to start your new job?
plz send me aptitude test questions on my email id bpraichur@gmail.com
foot is related to man in the same way hoof is related to...........
4_4_4_4=22 use all sign of maths
why should we hire the others waiting to be interviewed?
sir i need catholic syrian bank previous question papers fully. it will be helpful for me to greater extend .please do the needful to me.
At 6o'clock ,a watch strokes 6 times.The time between first and last is 30secs.At midnight 12o' clock how much time for all strokes?
In rail road there are some stations. Each station should have tickets to all other stations.If they add some new stations they need 46 more tickets.How many stations are there before and after adding the stations?
P pages read in d mins after day p+1 pages read in d+1 mins last day 379 pages done in 317 mins find p+4
what three specific job positions do you target from qatar airways group u.k?