Question bank AMC AUSTRALIA 2021

Each edge of this star is 2 cm long. What is its perimeter?

The value of 2000 − 200 + 20 − 2 is

What is the value of a in the diagram?

What is 50% more than $\frac12$?

Evaluate $\frac{1+3+5+7+9}{2+4+6+8+10}$.

Square ABCD has centre O. The shaded area is 16 square units. What is the length of the side of the square?

On the number line, which number is halfway between $10^2$ and $10^4$?

To feed a horse, Kim mixes three bags of oats with one bag containing 20% lucerne and 80% oats. If all the bags have the same volume, what percentage of the combined feed mixture is lucerne?

I have a solid block of wood in the shape of a cylinder. The top and bottom faces meet the curved side at right angles. Suppose that I slice the cylinder along a plane to create two smaller blocks of wood. Which of the following could not be the shape of the resulting faces created by the slice?

Diya timed herself cycling laps around her suburb. After five laps, her stopwatch indicated 18 minutes and 15 seconds. What was her average time per lap?

I have four consecutive odd numbers. The largest is one less than twice the smallest. Which of the following is the largest of the four numbers?

On a compact disc, uncompressed music data is stored as 44100 samples for each second of music, where each sample requires 4 bytes of data. Which of the following is closest to the number of bytes required to store 5 minutes of music on the disc?

In the figure, the value of x is

What is the equation of the line passing through (0, 0) that bisects the square in the diagram?

A standard dice numbered 1 to 6 with opposite sides adding to 7 is placed on a 2 by 2 square as shown. The dice is rolled over one edge onto each of the four base squares in turn and then back onto the original square, as indicated by the arrows. Which side of the dice is now facing upwards?

The two spinners shown are spun and the numbers that the arrows point to when they stop are recorded. For example, the numbers here are 3 and 6. What is the probability that the sum of the two numbers is even?

The area of the shaded region is given by

If k and n are positive integers and $\sqrt{10n+k}=k$, then the smallest possible value for k is

Two squares are drawn as shown. The smaller square covers $1/8$ of the larger square and the larger square covers $2/9$ of the smaller square. What is the ratio of the side length of the larger square to that of the smaller square?

Six identical darts fit inside a regular hexagon as shown. Each dart has three interior angles of 30° and one of 270°. What fraction of the large hexagon is shaded?