Question

. How many different three-letter initials can people have?

Answer 1

What type of question is this?

Answer 2

no

Answer 3

No, it's taking into account the amount of ways 3 letters can be arranged using our 26 letter alphabet.

Answer 4

Silly me..

Permutations And Combinations.. :)

Answer 5

:)

Answer 6

It is talking about "Different"

So, Repetition is not allowed, first of all.. :)

Answer 7

First letter can be filled in 26 ways as all 26 letters are there to choose from..

As you will use one letter for forming first letter, for second letter you will only have 25 ways to choose letters, and in the formation of third letter, you have 24 ways..


So number of ways are:

\(26 \times 25 \times 24\)

Answer 8

thanks my dear :)

Answer 9

i have one question .may i ask?

Answer 10

Yes sure.. :)

Answer 11

How many strings of five ASCII characters contain the
character @ (“at” sign) at least once? [Note: There are
128 different ASCII characters

Answer 12

I am unable to see the letters..

What have you done with letters? :P

Answer 13

nothing))))

Answer 14

. How many 5-element DNA sequences
a) end with A?
b) start with T and end with G?

Answer 15

ok help this question )))

Answer 16

In that five string, you are forming a string with 5 ASCII characters..

In that five characters, either 1st or 2nd or 3rd or 4th or 5th place can be @ character..

Answer 17

And I need some help too..

@sidsiddhartha

Answer 18

I think it is time to crown Mira..

So, @Miracrown can we get your help here??

Answer 19

think of those 5 ascii characters that does'nt contain @
now repetation is also allowed

Answer 20

so we can get total \[127^5\] no. of such combinations

Answer 21

now there are \[128^5\] no of strings of 5 ascii characters right?
result will be=\[=strings~without~@-strings~with~@\\=128^5-127^5\]

Answer 22

ok?

Answer 23

thanks so much)))

Answer 24

for for the second question --
there are 4 possible bases =A,T,G,C
so for ending with A