Math question How much would B equal

I am not sure if my problem contains enough data but here goes..
If B equals 17.24 on 1-2-1990 and C equals 2.99 on the same date there exist a -83% difference from B and C
So if C equals 16 cents on 1-2-1962 how much is B on the same date 1-2-1962

Not enough data, because unless you are stating the same percentage difference occurs on each set of dates, you need one more data point. The percentage difference given between the two on the same date/year is unnecessary, as that information is already obtainable from the data given.

Example would be to say that Stock C was valued at 16c per share on 1-2-1962, and Stock B was valued at Xc per share. If on the same day in 1990, Stock B holds a share price of $2.99, Stock C is worth $17.24, and they hold exactly the same share percentage difference as they did 28 years prior, what was the original valuation of Stock B? (92c)

Or you could say that each stock rose at the same rate over the same time period. Either way, you need that info.

B/0.16 = 17.24/2.99
B = 0.16*17.24/2.99
B = 0.922541806

(B - 16) / B = 0.83

=> B - 16 = 0.83 B

=> B - 0.83 B = 16

=> 0.17 B = 16

=> B = 16 / 0.17

=> B = 94.117