Darren filled boxes with tins of Orange juice and numbered the boxes in the order in which they were filled. He packed the 496th tin in box 21 then stopped for lunch. Box 21 was not completely filled. How many tins were in box 21?

Step-by-step explanation:

496 : 20 = 24 R 4

In box 21 were 4 tins.

16

Step-by-step explanation:

Darren completely filled each box before the 21st box. This means he completely filled 20 boxes. To find out how many tins fit in each box, divide:

496/20 = 24.8

This means each of the 20 preceding boxes held 24 tins. To get these filled, Darren used 20 (24) = 480 tins of juice.

This left Darren with 496-480 = 16 tins of juice to put in box 21 before lunch.