Answer:
Step-by-step explanation:
we have
step 1
Solve
substitute
step 2
Solve
substitute
step 3
Solve
therefore
Answer with explanation:
Number of Letters from which we have to make four-letter passwords
={A,B,C,D,E,F,G}=7
Since repetition of digit is not allowed.In Permutation order of arrangement is Important,while in combination order of arrangement is not Important.
Out of seven letters we have to select four letters, keeping in mind the order of Alphabets.So, we will use the concept of Permutation.
Number of ways of arrangement,that is to make four letter password from 7 Alphabets
So, total number of ways of making password from 7 alphabets=840 ways
Second Method⇒
Since repetition of alphabets is not allowed, first Alphabet can be chosen in 7 ways , second alphabet can be chosen in 6 ways, third alphabet can be chosen in 5 ways, fourth alphabet can be chosen from four alphabets.
So, total number of ways of making four letter password
=7×6×5×4
= 840 ways
Answer
about 4 hours and 20 minutes
Step-by-step explanation:
200 divided by 60 is 3.33 or 3 hours and 20 minutes, plus the extra hour
Yes because it is a higher number. 8 is higher then 3