How is it possible to know how much he started with? Or is it not asking for an exact amount?
        
             
        
        
        
Answer:
*helps*
Step-by-step explanation:
done (:P)
 
        
             
        
        
        
Answer:
Maureen earned $123.19 doing odd jobs
Step-by-step explanation:
The compound interest formula is given by:

Where A(t) is the amount of money after t years, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per unit year and t is the time in years for which the money is invested or borrowed.
In this question:
Compounded quarterly means that 
10 years, so 
9% interest, so 
There is $300.00 in the account, which means that 
How much did Maureen earn doing odd jobs?
This is P.





Maureen earned $123.19 doing odd jobs
 
        
             
        
        
        
Answer: 20%
Step-by-step explanation:
If we let the original amount be x, then after increasing it by 25%, we now have 1.25x
To get this back to x, we need to do 1.25x*(something) = x
this gives us that something = 1/1.25 = 0.8
meaning you need to decrease it by 100% - 80% = 20%
 
        
             
        
        
        
Find the average of the numbers(the middle number) by dividing 200 by 5 to get 40. Since the numbers count by two, we would add four to get the value of the last number: 44.