Answer:
About 31 years 
Step-by-step explanation:
Given data
Principal= $3500
Rate=  4.75% 
Final amount= $15,000
Time=??
The expression for time on compound interest is 
Calculate time, solve for t
t = ln(A/P) / r
substitute
Calculate time, solve for t
t = ln(15000/3500) / 0.0475
t= ln(4.2857)/ 0.0475
t= 1.4552/0.0475
t= 30.63 years
Hence it will take about 31 years 
 
        
             
        
        
        
Answer: 66
Step-by-step explanation: Basically you want to find the area of the whole shape and the white shape, which the whole shape is 96 and the white shape is 30, and subtract 96-30=66
 
        
                    
             
        
        
        
Answer:
its 21 obviously 
Step-by-step explanation:
 this is because 
<em>![8 {6 \times 58964 \sqrt[45 \sqrt{66x3 \times \frac{?}{?} } ]{?}  \times \frac{?}{?} }^{2}](https://tex.z-dn.net/?f=8%20%7B6%20%5Ctimes%2058964%20%5Csqrt%5B45%20%5Csqrt%7B66x3%20%5Ctimes%20%5Cfrac%7B%3F%7D%7B%3F%7D%20%7D%20%5D%7B%3F%7D%20%20%5Ctimes%20%5Cfrac%7B%3F%7D%7B%3F%7D%20%7D%5E%7B2%7D%20) </em>
</em>