Answer:
$53750
Explanation:
Sam deposit $12500 every year which grows at a simple interest of 3% and we have to calculate the total sum after 4 years. 
If Sam deposit $x with r% simple interest then the principal will grow after 4 years to 
![x[1 + (4r)/(100)]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t6jfjh4w74rfxxk0fa5n99cr8192h2uk5w.png) 
 
Again, for the second year $x investment with r% simple interest will grow to 
![x[1 + (3r)/(100)]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/jqv80gj7x1umzr7abry5lz2pi24t0k58y5.png) .
. 
Now, the third year $x investment with r% simple interest will grow to 
![x[1 + (2r)/(100)]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/eoz6edipnjzsqgjne891ygnna7vhxm2sgd.png) 
 
And finally the fourth year $x investment with r% simple interest will grow to 
![x[1 + (r)/(100)]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/tvpb0rydj3qurx9vfl77rcsjxl9cwel45q.png) 
 
Therefore, the total sum becomes  
![x[1 + (4r)/(100)] + x[1 + (3r)/(100)] + x[1 + (2r)/(100)] + x[1 + (r)/(100)]](https://img.qammunity.org/2020/formulas/mathematics/middle-school/gq7c2pqwe9trgs1qzxdj23vu74l1pvo3mh.png) 
 
= 
 
 
= 
 
 
So, in case of Sam the sum will be = 
 = $53750
 = $53750