how many words of $4$ consonants and $3$ vowels can be made from $12$ consonants and $4$ vowels? if all the letters are different?
Clash Royale CLAN TAG#URR8PPP
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my effort for this question is
I am selecting $4$ consonants from $12$ available consonants and $3$ from $4$ available vowels. After selecting $4$ consonants and $3$ vowels now I have $7$ letters in my hand now I am permuting them all with $7!$.
So the total number of words can be made is $12choose44choose37!$.
But the answer is $12choose44choose3$.
I would appreciate if anyone advises on this question.
discrete-mathematics permutations combinations
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up vote
2
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favorite
my effort for this question is
I am selecting $4$ consonants from $12$ available consonants and $3$ from $4$ available vowels. After selecting $4$ consonants and $3$ vowels now I have $7$ letters in my hand now I am permuting them all with $7!$.
So the total number of words can be made is $12choose44choose37!$.
But the answer is $12choose44choose3$.
I would appreciate if anyone advises on this question.
discrete-mathematics permutations combinations
Weird, at least for me it seems your answer is correct. Maybe the given answer assumes that the consonants need to stay in their own cluster before a cluster of vowels. Odd.
â Matti P.
Aug 14 at 7:35
1
Your answer is correct.
â N. F. Taussig
Aug 14 at 7:44
add a comment |Â
up vote
2
down vote
favorite
up vote
2
down vote
favorite
my effort for this question is
I am selecting $4$ consonants from $12$ available consonants and $3$ from $4$ available vowels. After selecting $4$ consonants and $3$ vowels now I have $7$ letters in my hand now I am permuting them all with $7!$.
So the total number of words can be made is $12choose44choose37!$.
But the answer is $12choose44choose3$.
I would appreciate if anyone advises on this question.
discrete-mathematics permutations combinations
my effort for this question is
I am selecting $4$ consonants from $12$ available consonants and $3$ from $4$ available vowels. After selecting $4$ consonants and $3$ vowels now I have $7$ letters in my hand now I am permuting them all with $7!$.
So the total number of words can be made is $12choose44choose37!$.
But the answer is $12choose44choose3$.
I would appreciate if anyone advises on this question.
discrete-mathematics permutations combinations
edited Aug 14 at 7:37
apanpapan3
125211
125211
asked Aug 14 at 7:16
Dharmendra Parmar
362
362
Weird, at least for me it seems your answer is correct. Maybe the given answer assumes that the consonants need to stay in their own cluster before a cluster of vowels. Odd.
â Matti P.
Aug 14 at 7:35
1
Your answer is correct.
â N. F. Taussig
Aug 14 at 7:44
add a comment |Â
Weird, at least for me it seems your answer is correct. Maybe the given answer assumes that the consonants need to stay in their own cluster before a cluster of vowels. Odd.
â Matti P.
Aug 14 at 7:35
1
Your answer is correct.
â N. F. Taussig
Aug 14 at 7:44
Weird, at least for me it seems your answer is correct. Maybe the given answer assumes that the consonants need to stay in their own cluster before a cluster of vowels. Odd.
â Matti P.
Aug 14 at 7:35
Weird, at least for me it seems your answer is correct. Maybe the given answer assumes that the consonants need to stay in their own cluster before a cluster of vowels. Odd.
â Matti P.
Aug 14 at 7:35
1
1
Your answer is correct.
â N. F. Taussig
Aug 14 at 7:44
Your answer is correct.
â N. F. Taussig
Aug 14 at 7:44
add a comment |Â
1 Answer
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I think you are correct
To take a simpler example, with two consonants from three $R,S,T$ and one vowel from two $A,I$, there are $3C2 cdot 2C1 cdot 3! = 36$ possibilities namely $$RSA, RSI,STA,STI,TRA,TRI,SRA,SRI,TSA,TSI,RTA,RTI,$$ $$RAS, RIS,SAT,SIT,TAR,TIR,SAR,SIR,TAS,TIS,RAT,RIT,$$ $$ARS, IRS,AST,IST,ATR,ITR,ASR,ISR,TSA,ITS,ART,IRT$$
not $3P2 cdot 2P1 = 12$, which would just be the first row in my example of having all the consonants first and then all the vowels
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
I think you are correct
To take a simpler example, with two consonants from three $R,S,T$ and one vowel from two $A,I$, there are $3C2 cdot 2C1 cdot 3! = 36$ possibilities namely $$RSA, RSI,STA,STI,TRA,TRI,SRA,SRI,TSA,TSI,RTA,RTI,$$ $$RAS, RIS,SAT,SIT,TAR,TIR,SAR,SIR,TAS,TIS,RAT,RIT,$$ $$ARS, IRS,AST,IST,ATR,ITR,ASR,ISR,TSA,ITS,ART,IRT$$
not $3P2 cdot 2P1 = 12$, which would just be the first row in my example of having all the consonants first and then all the vowels
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
add a comment |Â
up vote
2
down vote
I think you are correct
To take a simpler example, with two consonants from three $R,S,T$ and one vowel from two $A,I$, there are $3C2 cdot 2C1 cdot 3! = 36$ possibilities namely $$RSA, RSI,STA,STI,TRA,TRI,SRA,SRI,TSA,TSI,RTA,RTI,$$ $$RAS, RIS,SAT,SIT,TAR,TIR,SAR,SIR,TAS,TIS,RAT,RIT,$$ $$ARS, IRS,AST,IST,ATR,ITR,ASR,ISR,TSA,ITS,ART,IRT$$
not $3P2 cdot 2P1 = 12$, which would just be the first row in my example of having all the consonants first and then all the vowels
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
add a comment |Â
up vote
2
down vote
up vote
2
down vote
I think you are correct
To take a simpler example, with two consonants from three $R,S,T$ and one vowel from two $A,I$, there are $3C2 cdot 2C1 cdot 3! = 36$ possibilities namely $$RSA, RSI,STA,STI,TRA,TRI,SRA,SRI,TSA,TSI,RTA,RTI,$$ $$RAS, RIS,SAT,SIT,TAR,TIR,SAR,SIR,TAS,TIS,RAT,RIT,$$ $$ARS, IRS,AST,IST,ATR,ITR,ASR,ISR,TSA,ITS,ART,IRT$$
not $3P2 cdot 2P1 = 12$, which would just be the first row in my example of having all the consonants first and then all the vowels
I think you are correct
To take a simpler example, with two consonants from three $R,S,T$ and one vowel from two $A,I$, there are $3C2 cdot 2C1 cdot 3! = 36$ possibilities namely $$RSA, RSI,STA,STI,TRA,TRI,SRA,SRI,TSA,TSI,RTA,RTI,$$ $$RAS, RIS,SAT,SIT,TAR,TIR,SAR,SIR,TAS,TIS,RAT,RIT,$$ $$ARS, IRS,AST,IST,ATR,ITR,ASR,ISR,TSA,ITS,ART,IRT$$
not $3P2 cdot 2P1 = 12$, which would just be the first row in my example of having all the consonants first and then all the vowels
answered Aug 14 at 7:38
Henry
93.4k471149
93.4k471149
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
add a comment |Â
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
+1 Very convincing. Counting is enough.
â drhab
Aug 14 at 9:24
add a comment |Â
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Weird, at least for me it seems your answer is correct. Maybe the given answer assumes that the consonants need to stay in their own cluster before a cluster of vowels. Odd.
â Matti P.
Aug 14 at 7:35
1
Your answer is correct.
â N. F. Taussig
Aug 14 at 7:44