We are given two compounds A and B, and their rate of consumption.
We are supposed to find the initial amount of each compound.
We have, Amount of compound A left after t seconds = 30000(12) t
It is a linear function.
After 1 sec, amount of A present = 30000(12)(1) = 360000
After 2 sec, amount of A present = 30000(12)(2) = 720000
Increase in amount of compound A in 1 sec = 720000 - 360000 = 360000
Amount B after 1 sec = 12000
Amount of B after 2 sec = 6000
Amount of B after 3 sec = 3000
We see that each second, the amount of B is reducing by half.
So, during the experiment, compound B is consumed to produce compound A.
Initial amount of compound A = 0 mg
Initial amount of compound B = 2* 12000 =24000 mg