simple probability question (1 Viewer)

[bleakarcher]

In Tasmania, a car license consists of two letters followed by four digits. Find how many of these are possible if the second letter is X and the third digit is 3.

Thanks

 

[Gujju]

we havent done probability in our school and i have no idea of the method but ill give it a go!

for letters its 26....then for numbers there are three digits that can change so 9 in each...so 26 x 9 x 9= 2106

NOTE- this is complete guess and i would recommend to check it with an experienced person...

EDIT- its 10 for each not 9....so 26 x 10 x 10= 2600

 

[bleakarcher]

yeh I got 2600 but answers at the back of the cambridge textbook say 26000...

 

[zeebobDD]

two letters and four digits so first like theres 25 possible ways second one is already chosen
first digit theres 9 second 8 third already chosen and fourth 7

so 25*9*8*7 = 12600

i assume the digits are 0-9 LOL at me :L

wait you didnt mention if they repeat or not?

 

[Gujju]

yeh I got 2600 but answers at the back of the cambridge textbook say 26000...

i am total idiot...its 26..and 10 each for three digits...so 26 x 10 x 10 x 10= 26000 there u go

 

[EpikHigh]

In Tasmania, a car license consists of two letters followed by four digits. Find how many of these are possible if the second letter is X and the third digit is 3.

Thanks

Alright so first of all there has to be two letter and the second letter has to be X so its 26 x 1 right? which is just 26, then there are only 3 digits that can be used in the licence plate so 26 x 10^3 = 26000.

God, I love perms and combs.

 

[Peeik]

Wouldnt the solution just be 26 * 10*10*10 = 26000?

 

[Carrotsticks]

In Tasmania, a car license consists of two letters followed by four digits. Find how many of these are possible if the second letter is X and the third digit is 3.

Thanks

LX DD3D

L = Letter
D = Digit.

First Letter has 26 options.

First Digit has 10 options.

Second Digit has 10 options.

Last Digit has 10 options.

26 x 10 x 10 x 10 = 26000

 

[zeebobDD]

you should include "repetition allowed in your question next time"

 

[Timske]

yeh I got 2600 but answers at the back of the cambridge textbook say 26000...

It is 26000, Letters in alphabet is 26, and there are 10 digits. a car license consists of two letters followed by four digits

Find how many of these are possible if the second letter is X and the third digit is 3. Since one letter and a digit is chosen we are left with

26 * 10 * 10 * 10 = 26000

 

[bleakarcher]

Isn't the third digit fixed though?

 

[EpikHigh]

you should include "repetition allowed in your question next time"

Usually the question will state if there IS NOT repetition. If there is nothing stated you usually would just assume it's allowed because it doesn't say it isn't.

 

[bleakarcher]

It is 26000, Letters in alphabet is 26, and there are 10 digits. a car license consists of two letters followed by four digits

Find how many of these are possible if the second letter is X and the third digit is 3. Since one letter and a digit is chosen we are left with

26 * 10 * 10 * 10 = 26000

OMGGGGGGZZZZZZZZZZZZZZZZZZZZZZZZ

My mind told me that there were 3 digits for some reason..

Alright thanks guys.

 

[Timske]

Isn't the third digit fixed though?

yeah but theres 4 digits, so thers 3 digits left

 

[EpikHigh]

Isn't the third digit fixed though?

It's a 4 digit number plate, the last number has to be 3, so that's 1 possible combination followed by 10^3

 

[Nooblet94]

OMGGGGGGZZZZZZZZZZZZZZZZZZZZZZZZ

My mind told me that there were 3 digits for some reason..

Alright thanks guys.

I make mistakes like that all the time!

 

[Frostbitten]

If there were no restrictions, it would be 26 x 26 x 10 x 10 x 10 x 10
But one letter slot is taken up and one number slot is taken up, so you ignore them.
It now becomes 26 x 10 x 10 x 10 = 26000
Or in the permutation format (nPr) which you would use the calculator for: 26P1 x 10P1 x 10P1 x 10P1 = 26000
n = number of objects available
r = the amount needed to be chosen

Pretty much what everyone has said before XD