Explanation:
The dimensions of the box as given is
28 by 15 by 20.
Therefore writing the lower bound and the higher bound for the box dimensions respectively are --
Box :
Length (27.5 , 28.5)
Width (14.5 , 15.5)
Height (19.5 , 20.5)
Similarly writing the disc dimensions with their lower and higher bounds respectively as --
Disc :
Length (1.45 , 1.55)
Width (14.25 , 14.35)
Height (19.25, 19.35)
Therefore, using the lower bounds of the box and the upper bounds of the discs,
14.35 < 14.5
19.35 < 19.5
So, 17
1.55 = 26.35
And, 26.35 < 27.5
Therefore, 17 discs can definitely fit in the box.