PSLE
Seth packed 380 croissants into large and small boxes. He filled each large box with 14 croissants and each small box with 8 croissants. All the boxes were full and no croissants were left over. What was the least number of boxes used by Seth?
To have the least number of boxes, Seth had to use as many as large boxes as possible.

If Seth used only large boxes,
number of large boxes used
= 380 ÷ 14
= 27 r 2 (x) There should be no remaining croissants left.

If 27 large boxes are used, there are 2 croissants left, Seth had to use less large boxes so that the rest of the croissants were packed in small boxes.

If Seth used 26 large boxes,
number of croissants to be packed in small boxes
= 380 - (26 x 14)
= 380 - 364
= 16

Number of small boxes needed to pack 16 croissants
= 16 ÷ 8
= 2 (✓) There is no remaining croissants left.

Least number of boxes that Seth used
= 26 + 2
= 28

Answer(s): 28