Three gentlemen and three ladies are candidates for two vacancies. A voter has to vote for two candidates. In how many ways can one cast his vote?
A. 9
B. 30
C. 36
D. 15
Answer: Option D
Solution(By Examveda Team)
There are 6 candidates and a voter has to vote for any two of them. So, the required number of ways is, $$\eqalign{ & { = ^6}{{\text{C}}_2} \cr & = \frac{{6!}}{{2! \times 4!}} \cr & = 15 \cr} $$This Question Belongs to Arithmetic Ability >> Permutation And Combination
I feel that the answer is wrong
since after casting 1 vote, he has 5 candidates to choose from
so the answer should be 30 (6C1*5C1)
as per the solution given the person is straightaway choosing 2 people out of 6 which is wrong.
this is wrong.! There will be 30 different ways to vote.
M1M2, M1M3, M2M1, M2M3, M3M1, M3M2
W1W2, W1W3, W2W1, W2W3, W3W1, W1W2,
W1M1, W1M2,W1M3, W2M1, W2M2,W2M3,
W3M1, W3M2,W3M3, M1W1, M1W2, M1W3,
M2W1, M2W2, M2W3, M3W1, M3W2, M3W3
1 gentlemen and(*) 1 lady or (+) 2 gentleman
or(+) 2 ladies =
=3c1*3c1 + 3c2 +3c2
=9+6+6
=15
WHY TAKE 4! ?