Level 2
The first three figures of a sequence are shown. The table records the number of shaded and unshaded rhombuses in each figure.

1. Find the number of unshaded rhombuses in Figure 10?
2. Find the number of shaded rhombuses in Figure 40?
3. Which figure number has 804 shaded rhombuses?

Level 3
The patterns show a sequence of shapes. Each shape has a number of small right-angled triangles. A dot is placed at each point where there is a vertex of one or more right-angled triangles. The total number of dots and the number of small right-angled triangles of each figure is shown in a table.

1. Find the total number of dots required to form Pattern 4.
2. Find the total number of dots required to form Pattern 20.
3. Find the number of small right-angled triangles in Pattern 50.

Level 3
The figure shows a tank made up of 3 sections. Cuboid A with a square base of side 4 cm and height 30 cm. Cube B with a side of 12 cm. Cuboid C that is 60 cm by 20 cm by 40 cm. Water from a tap above flows down at a rate of 1.2 litres per minute while water is drained out from the bottom at a rate of 1 litre per minute. How long did it take to fill up the tank to a height of 66 cm from the base? Give the answer in minutes correct to nearest whole number.

Level 2
The figure consists of squares of side 4 cm. Find the area of the shaded parts.

Level 3
Some patterns of shaded and unshaded small triangles is given. The unshaded triangles are those which have at least one side on the edge of the big triangle. All of the other small triangles are shaded. The table below shows numbers of small triangles.

1. Find the total number of triangles in Pattern 80.
2. Find the number of shaded triangles in Pattern 40.
3. Find the number of unshaded triangles in Pattern 50.