a mini license plate for a toy care must consist of a letter followed by 2 numbers. each letter must be C,A, or R. each number must be a 3 or a 7. Repetition of digits is permitted. Determine the number of points in the sample space. construct a tree diagram. determine the probability of creating a mini license plate with a 7.

Question

a mini license plate for a toy care must consist of a letter followed by 2 numbers.  each letter must be C,A, or R.  each number must be a 3 or a 7.  Repetition of digits is permitted.  Determine the number of points in the sample space.  construct a tree diagram.  determine the probability of creating a mini license plate with a 7.

anonymous · Answer

help please

kropot72 · Answer

Can you work out the ways of arranging the numbers 3 and 7 as a pair when you can have the pairs 33 and 77?

anonymous · Answer

i don't understand what you mean

kropot72 · Answer

I can find 4 ways of arranging the two digits: 33, 37, 77, 73. Each of these 4 ways can be preceded by the letter C, A or R. 
So each of the 3 letters has 4 possible pairs of digits following it. Can you now work out the sample space?

anonymous · Answer

so the sample space if i'm figuring correctly is c33a37r77, c33a37r73, c37a77r73, c77a73r33 (am i on the right track here?

kropot72 · Answer

Well you missed C73, A33 and R37 and doubled up on C33, A37 and R73

anonymous · Answer

OK SORRY ABOUT THAT

anonymous · Answer

SO I'VE GOT THAT, BUT THEN I GET CONFUSED

kropot72 · Answer

So the sample space has 12 points
C33, C37, C77, C73
A33, A37, A77, A73
R33, R37, R77, R73
How many of the 12 arrangements have the digit 7?