Answer:
Please see attached picture for full solution.
290-10=280
280 is one standard deviation below.
All that are above mean is 50%.
One standard deviation below is 34%.
50%+34%=84% all of these bags weigh more than 280 g.
So,
100%-84%=16% should be bags that are less than 280 g.
Answer is b) 16 %.
The volume of a rectangular prism is L * W * H.
We are looking for whole numbers that multiply to 28.
There are 10 possible molds.
L, W, H
-------------
28, 1, 1
1, 1, 28
14, 2, 1
1, 14, 2
1, 2, 14
7, 4, 1
4, 1, 7
7, 1, 4
7, 2, 2
2, 2, 7