To answer this question, use permutation since the order of the letter matters. There are 7 letters and only 4 are to be used for the code. This  is a permutation of 7 taken 4 (7P4) which is equal to 840. Thus, the sample space is 840.
For the next questions, there are 3 vowels for as the first letter, only 6 letters are available for the second, 5 on the next, and 4 on the last. Multiplying these numbers give 360. To solve for probability, divide this number with the sample space. Thus, the answer is 3/7. 
        
             
        
        
        
Answer:
The trip was 45 minutes
Step-by-step explanation:
you take 60 minutes which is an hour and subtract 15 to get 45 minutes
 
        
             
        
        
        
Answer:
The second one, -11/12
Step-by-step explanation:
I used a website so sorry I don't have an explanation
 
        
             
        
        
        
Answer:
y = 2x - 5
Step-by-step explanation:
y-intercept form is y = mx + b, where m is the slope and b is the y-intercept. We know the slope is 2, so all that's left is to find the y-intercept. To do this, for every 1 we subtract from x in (4,3), we take away 2 from y because the slope is two. We keep doing this until x is zero. The remaining y-value is the y-intercept.  
 
        
                    
             
        
        
        
answer
94
set up equations
average = total points / number of tests
total points = test1 + test2 + test3 + test4+ test5
total points = 88 + 94 +89 + 85 + test5
total points = 356 + test5
plug total points into first eqation and rearrange
average = total points / number of tests
average = (356 + test5)/number of tests
average * number of tests = 356 + test5
test5 = average * number of tests - 356
plug in values for average and number of tests
test5 = average * number of tests - 356
test5 = 90 * 5 - 356
test5 = 94