Workers paint a house over two days. They work for one third of a day on the first day and half of a day on the second. How many hours do they work altogether?
Uncle Lam originally has a square garden. After selling two pieces, the remaining garden has the outline shown. Find its current area in square metres.
Cindy has a 3 × 3 × 3 Rubik’s cube. She drops it and it breaks into two pieces. One piece is shown. At least how many small cubes are in the other piece?
A rope of length 2 m is glued onto a cubic box, with both ends meeting at the red point. The three visible faces and visible rope segments are shown. What is the maximum total surface area of the cube?
Grading convention: use the illustrated straight, edge-parallel segments; the red point and the rope endpoint on the back-right edge are at mid-height. The remaining rope lies on the unseen faces.
The graph shows Marie’s distance from home during one hour. She goes to a bookstore, then a supermarket, then home. Excluding all resting time, what is her average speed?
Editorial convention: all travel follows the same route, so the changes in distance from home give segment lengths.
Nine children sit around a circle in order, numbered 1 to 9. Child 1 has one ball and child 2 has two balls. Any six consecutive children have 14 balls altogether. How many balls does child 3 have?
A special water fern doubles in area every four days. Scientists begin with 3 cm² on 27 April 2020. On 31 December 2020 they divide all the fern into 10 cm² samples and have a cm² left over. Find a.