Answer:
Here is the ans..hope it helps:)
Answer:
I think number 2 is the answer, but 4 could be the answer.
Answer:
1/2 or 0.5
Step-by-step explanation:

Since it is a four combination lock or permutation and she wants the last digit to be seven we have_,_,_,7
The first digit: Since we need it to be any number except 7 we have 9 possibilities.For the second digit: We have 8 possibilities since the numbers can't be repeated and we already chose 7 to be the last digit and any other digit to be the first digit.For the third digit: there are 7 possibilities since we already chose three numbers and these cannot be repeated.
We have the following:9*8*7=504