tcs
Exam
Numerical Ability
Permutation and Combination
Q1. 1 red flag, 3 white flags and 2 blue flags are arranged in a line
such that:
I. No two adjacent flags are of the same colour
II. The flags at the ends are of 2 different colours.
In how many different ways the flags be arranged?
Read Solution (Total 5)
-
- Case 1:
W_W_W_
Case 2:
_W_W_W
we have 3 slots free where we have to arrange 3 flags.
3 flags can be arranged in 3! ways.
out of 3 flags, two are blue (identical).
Taking care of the 2 indistinguishable choices, we get, 3!/2! ways per case.
Since there are 2 cases, we get 2*3!/2! - 6 years agoHelpfull: Yes(14) No(3)
- Red flags are represented by R
White flags are represented by W
Blue flags are represented by B
And vacant spaces are represented by _
As No 2 adjacent flags are of the same colour, these are the 2 possible arrangements-
1. W_W_W_
OR
2. _W_W_W
Now, 1 red flag and 2 blue flags have to be arranged in these vacant places.
Hence, these 3 flags can be arranged in 3!/2! ways = 3 ways { RBB, BRB, BBR}
If we consider the 1st possible arrangement, then also these 3 flags can be arranged in 3 ways and this is applicable to the 2nd possible arrangement also.
So, Total number of ways = 3 + 3 ways
= 6 ways - 5 years agoHelpfull: Yes(4) No(1)
- Answer is 36.. Because No two adjacent flags are of the same color..so assume 1 arrangement as B W B W R W.. so to arrange 2 blue balls,ways are 2!.. to arrange 3 white balls,ways are 3!.. & to arrange 1 red ball,ways are 1!.. & also , we are not confirm about which ball should come first, so again there are 3 ways. So,total = 2!*3!*1! * 3 = 36
- 6 years agoHelpfull: Yes(2) No(7)
- WBWBWR
WBWRWB
WRWBWB
BWBWRW
BWRWBW
RWBWBW
WBRWBW
WRBWBW
WBWBRW
WBWRBW
10 WAYS - 5 years agoHelpfull: Yes(1) No(6)
- 6 ways is the answer
- 5 years agoHelpfull: Yes(1) No(2)
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