How do I work out this problem?

A company making silver plated objects uses an electroplating process.


In this process the mass of silver, m grams, deposited is proportional to the time, t hours, during which the process takes place.


When t=5.5, m=38.5


Calculate m when t=10.5 %26amp; calculate t when m=105


Thanks in advance!How do I work out this problem?
Since m is proportional to t, m/t is a constant.





1.


m/10.5 = 38.5/5.5


Solve for m,


m = 73.5 g





2.


105/t = 38.5/5.5


Solve for t,


t = 15 hr