Question

A batch of bottles was packed in 25 boxes with 12 bottles in each box. If the same batch is packed using 20 bottles in each box, how many boxes would be filled?

Answer 1

Let the number of boxes filled, by using 20 bottles in each box, be x. 
The following table is obtained.

Number of bottles	4	x
Number of boxes	3	4

More the number of bottles, lesser will be the number of boxes. 
Hence, the number of bottles and the number of boxes required to pack these are inversely proportional to each other.
Therefore, 
\(12 × 25 = 20× x\)
\(x = \frac{12 × 25 }{ 20} \)
\(=15\)
Hence, the number of boxes required to pack these bottles is 15.