PSLE
Michael packed 414 croissants into large and small boxes. He filled each large box with 16 croissants and each small box with 6 croissants. All the boxes were full and no croissants were left over. What was the least number of boxes used by Michael?
To have the least number of boxes, Michael had to use as many as large boxes as possible.

If Michael used only large boxes,
number of large boxes used
= 414 ÷ 16
= 25 r 14 (x) There should be no remaining croissants left.

If 25 large boxes are used, there are 14 croissants left, Michael had to use less large boxes so that the rest of the croissants were packed in small boxes.

If Michael used 24 large boxes,
number of croissants to be packed in small boxes
= 414 - (24 x 16)
= 414 - 384
= 30

Number of small boxes needed to pack 30 croissants
= 30 ÷ 6
= 5 (✓) There is no remaining croissants left.

Least number of boxes that Michael used
= 24 + 5
= 29

Answer(s): 29