Sets
(Counting words). How many 4-letter words do not begin
or end with a vowel?
[Here the alphabet is assumed to be {a, b, c, . . . , z} and the set of vowels is
{a, e, i, o, u}. A (mathematical) word is any string of letters: it need not be
a word in any language.]
rep for good help
or end with a vowel?
[Here the alphabet is assumed to be {a, b, c, . . . , z} and the set of vowels is
{a, e, i, o, u}. A (mathematical) word is any string of letters: it need not be
a word in any language.]
rep for good help
surely you could say there are 21 different possibilities for the 1st and 4th letters, and 26 different possibilities for the 2nd and 3rd letters.. so there are 21*21*26*26 possibilities?
not sure if thats correct just a quick idea
not sure if thats correct just a quick idea
Original post by just george
surely you could say there are 21 different possibilities for the 1st and 4th letters, and 26 different possibilities for the 2nd and 3rd letters.. so there are 21*21*26*26 possibilities?
not sure if thats correct just a quick idea
not sure if thats correct just a quick idea
ok how sure are you?
well between 0 and 9 inclusive there are 10 digits.. and there are 100 2 digit numbers if you include 00, so in that case there are 10 possible 1st digits and 10 possible 2nd digits giving 10*10 possible 2 digit numbers.. there are also 10*10*10 3 digit numbers and 10*10*10*10 4 digit numbers. so by the same logic my thing works, providing there is no problem with repeating letters (e.g. BBBB is a word?) etc..
short version.. pretty sure
short version.. pretty sure
Original post by just george
well between 0 and 9 inclusive there are 10 digits.. and there are 100 2 digit numbers if you include 00, so in that case there are 10 possible 1st digits and 10 possible 2nd digits giving 10*10 possible 2 digit numbers.. there are also 10*10*10 3 digit numbers and 10*10*10*10 4 digit numbers. so by the same logic my thing works, providing there is no problem with repeating letters (e.g. BBBB is a word?) etc..
short version.. pretty sure
short version.. pretty sure
ok cheers!
Quick Reply
Related discussions
- What sets were/are you in at school?
- What are sets based on?
- Help I'm in set 2 for maths and set 3 for english
- Does anyone feel like their set in school let them down?
- Have you ever gone down sets only to go back up again?
- The higher the set you are in, does it mean you have better teachers?
- Was anyone allowed to choose their set in school?
- Top of the criminal bar?
- Move up sets in year 10
- Did I make the right decision?
- I Want To Move Up A Set In Maths Help!!😖
- Topology
- maths sets in year 9
- How do you get moved up a set ?
- Why is it that I was able to do combined science higher in set 5 but not in set 6?
- I really want to be in set 1/2 science, currently in year 8!!
- Can I move up sets in year 10 and how will that affect my gcse's
- How likely are you to pass science if you are in set 6?
- Why is it that some teachers let me have my way in school?
- How necessary is a first in order to become a barrister?
Latest
Trending
Last reply 1 day ago
Did Cambridge maths students find maths and further maths a level very easy?Last reply 2 weeks ago
Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths
71
Trending
Last reply 1 day ago
Did Cambridge maths students find maths and further maths a level very easy?Last reply 2 weeks ago
Edexcel A Level Mathematics Paper 2 unofficial mark scheme correct me if wrongMaths
71
