Hello!
To start, since you already know that you can drive 3000 miles in 75 hours, but you need to know how long it will take to drive 4000 miles, you can solve using a proportion, where x is the amount of hours:
3000/75=4000/x
When you have set this up, cross multiply:
3000*x=75*4000
After you have cross multiplied, you will result in this:
3000x=300000
Then, solve for x and you will get x=100, meaning it will take Cheyenne 100 hours to drive 4000 miles.
        
             
        
        
        
Answer:
800
Step-by-step explanation:
 
        
                    
             
        
        
        
Represent these consecutive numbers (assuming that they are all integers):
x
x+1
x+2
x+3
x+4
x+5
and so on
x+8
x+9 is the tenth number.  x+9 = 10, so x = 9.
Think of it this way:  there are 10 consecutive numbers, and the last one is 10.
Working backwards, we get the sequence 10, 9, ... 3, 2, 1.
The sum of such an arith sequence is equal to the count of the numbers times the average of the first and last terms:
sum here = 10(1+10)/2 = 5(11) = 55          (answer)