Mathematics, about class 8

A baker has 28 buns and 42 rolls. She packs them into identical bags with nothing left over. Each bag has the same number of buns and the same number of rolls. What is the greatest number of bags she can make?

1. A2 bags
2. B14 bags
3. C7 bags
4. D84 bags

A square garden has an area of 121 m². How much fence goes all the way round it?

1. A11 m
2. B30.25 m
3. C44 m
4. D22 m

The North library has 6 × 10⁴ books. The South library has 2 × 10⁵ books. Which sentence is true?

1. AThe South library has more books, because its power of ten is larger.
2. BThe North library has more books, because 6 is bigger than 2.
3. CThe North library has more books, because 6 × 4 = 24 is more than 2 × 5 = 10.

What is 7 + 5 × 6 − 8 ÷ 2?

1. A32
2. B68
3. C14.5
4. D33

Which of these is 9/40 written as a decimal?

1. A0.94
2. B0.225
3. C4.444...
4. D0.0225

A farmer picks 240 mangoes. 35% of them are ripe. How many mangoes are ripe?

1. A205 mangoes
2. B8 400 mangoes
3. C84 mangoes
4. D6.9 mangoes

A shape on a grid has a corner at (4, 7). The shape is reflected in the mirror line y = 5. Where is the image of that corner?

1. A(4, 5)
2. B(6, 7)
3. C(4, 12)
4. D(4, 3)

A wheel has 10 spokes, spaced equally round the centre. What is the smallest turn about the centre that makes the wheel look the same?

1. A10°
2. B36°
3. C72°
4. D360°

A hexagonal prism has 8 faces and 12 corners. Use faces + corners − edges = 2. How many edges does it have?

1. A18 edges
2. B20 edges
3. C22 edges
4. D12 edges

A spinner has 10 equal sections. 7 are green and 3 are yellow. You spin once. Which sentence describes landing on green?

1. AIt is unlikely. The probability is 0.7.
2. BIt is likely. The probability is 7.
3. CIt is an even chance. The probability is 0.5.
4. DIt is likely. The probability is 0.7.

Solve 6x − 5 = 2x + 15.

1. A5
2. B2.5
3. C3.75
4. D10

A straight line goes from (1, 10) to (4, 1). What is its gradient?

1. A−3
2. B3
3. C−9
4. D−0.33

A line goes through (0, −2) and (3, 10). What is the equation of the line?

1. Ay = 4x + 2
2. By = 12x − 2
3. Cy = 4x − 2
4. Dy = −2x + 4

A stadium has 58 rows of seats with 349 seats in each row. Round each number to one digit to estimate the number of seats.

A shop has 7 rolls of cloth with 20 m in each roll. It also has 36 m of loose cloth. All of it is cut into pieces of 8 m. How many pieces are there?

A mat is 0.8 m long and 0.45 m wide. What is its area in m²?

A path is 8 cm long on a map. The scale of the map is 1 : 20 000. How long is the real path, in km?

A team of 9 tailors sews a batch of uniforms in 8 days. How many days would a team of 6 tailors take?

A round flower bed has a diameter of 12 m. Use 3.14 for π. What is its area?

A jar holds 5 red, 7 blue and 3 green sweets of the same size and shape. You take one without looking. What is the chance that it is not blue? Write it in simplest form.

A tile pattern uses 9, 14, 19 and 24 tiles in its first four shapes. How many tiles does the 40th shape use?

A row is made from 4 equal planks and one block 35 cm long, laid end to end. The row is 155 cm long. How long is each plank?

A bag holds 3 red beads and 7 blue beads of the same size. Ali picks one bead, looks, and puts it back. He does this 200 times. About how many times do you expect a red bead?

(a)How many litres does the tank hold when it is full? [2 marks]

(b)How many minutes does the tap take to fill the tank? [1 mark]

(c)The tank has no lid. Mei paints the outside of its four sides and its base. What area does she paint? [2 marks]

(d)The tap is turned off when the tank is full. Leila draws a graph of the litres in the tank for the first 20 minutes. She says the litres are in direct proportion to the minutes all the way along her graph. Is she right? Explain. [2 marks]