PSLE
Peter packed 216 scones into large and small boxes. He filled each large box with 16 scones and each small box with 6 scones. All the boxes were full and no scones were left over. What was the least number of boxes used by Peter?
To have the least number of boxes, Peter had to use as many as large boxes as possible.

If Peter used only large boxes,
number of large boxes used
= 216 ÷ 16
= 13 r 8 (x) There should be no remaining scones left.

If 13 large boxes are used, there are 8 scones left, Peter had to use less large boxes so that the rest of the scones were packed in small boxes.

If Peter used 12 large boxes,
number of scones to be packed in small boxes
= 216 - (12 x 16)
= 216 - 192
= 24

Number of small boxes needed to pack 24 scones
= 24 ÷ 6
= 4 (✓) There is no remaining scones left.

Least number of boxes that Peter used
= 12 + 4
= 16

Answer(s): 16