Question 132815
The picture is a rectangle formed by removing a constant from both dimensions of the outer frame 28 x 32.

(28 - c)(32 - c) = 192
896 - 60c + c^2 = 192
c^2 - 60c + 704 = 0
(c - 44)(c - 16) = 0

so c = 44 or c = 16.

Now c represents twice the frame width, because the frame removes area from both sides (and from top AND bottom) of the picture. 44 cm is bigger than the picture, so it's not an answer. If c = 16, then the picture is 12cm by 16cm = 192 cm^2, which checks.

Therefore the frame is 8 cm wide.