Question bank AMO 2021

Question 1

Tom had 60 fish crackers. He ate half of them, then gave 10 to his best friend. How many fish crackers does he have now?

1. 25
2. 22
3. 20
4. 18
5. 15

Question 2

The whole triangular cake costs 18 dollars. It is divided into equal small triangles. Carla buys the shaded pieces. How many dollars should she pay?

1. 4
2. 6
3. 8
4. 10
5. 12

Question 3

Mary has blue, green, and red markers. She colors three different birds, using a different color for each bird. In how many ways can she color them?

1. 10
2. 8
3. 6
4. 4
5. 5

Question 4

Find the sum of the largest and smallest numbers in this group: $305,530,503,725,752,527$.

1. 1033
2. 1030
3. 1057
4. 832
5. 1477

Question 5

A rectangle was divided into small squares. Some internal lines have faded. How many small squares were there originally?

1. 35
2. 21
3. 18
4. 40
5. 28

Question 6

Taylor uses a broken ruler marked in centimeters. The stick is placed as shown. What is its length in centimeters?

1. 24
2. 14
3. 18
4. 38
5. 32

Question 7

Anne had 12 apples and sold them for 2 dollars each at a school event. At the end, one third of the apples remained. How many dollars did she collect from selling apples?

1. 8
2. 10
3. 12
4. 16
5. 18

Question 8

The marble shapes follow a pattern from left to right. The first has 1 marble and the second has 5. How many marbles are in the next shape after all four shapes shown?

1. 12
2. 15
3. 16
4. 17
5. 21

Question 9

A playground has areas A, B, and C. There are 3 paths from A to B and 4 from B to C. How many ways can you go from A to C via B, choosing one path for each stage?

1. 7
2. 10
3. 12
4. 34
5. 43

Question 10

On Saturday, Maria read from 11:45 in the morning to 1:15 in the afternoon. How long did she read?

1. One hour and five minutes
2. One hour and fifteen minutes
3. One hour and thirty minutes
4. Two hours
5. Two hours and forty-five minutes

Question 11

Pencils cost 50 cents each and erasers cost 40 cents each. Alice had 5 dollars. She bought 3 pencils and 2 erasers. How many cents does she have left?

1. 230
2. 300
3. 270
4. 245
5. 156

Question 12

Megan began reading at 9:20 a.m. She stopped after 45 minutes and went for a walk. At what time did she stop reading?

1. 9:45
2. 10:05
3. 10:15
4. 10:20
5. 11:00

Question 13

The large square is divided as shown. T marks a small shaded triangle. How many triangles of the same size and shape as T would cover the whole square?

1. 6
2. 8
3. 10
4. 12
5. 16

Question 14

How many squares of all sizes are in the picture?

1. 12
2. 13
3. 14
4. 15
5. 16

Question 15

The numbers 1 through 9 are each written once in the grid. A, B, and C cover three numbers. Each row has the same sum. What number is covered by B?

1. 2
2. 5
3. 6
4. 7
5. 8

Question 16

Six dots lie on a circle. Lily draws one straight segment between every pair of dots. How many segments does she draw?

Question 17

Katie makes 12 paper snowflakes per hour and Matt makes 18 per hour. Working together at these rates, how many hours do they need to make 120 snowflakes?

Question 18

Sam has eight sticks of lengths $2,5,8,11,14,17,20,23$ inches. He joins all of them end to end to form a loop. How long is the loop in inches?

Question 19

On the number line, a hidden number is equally far from 42 and 72. What is that number?

Question 20

A square chocolate bar costs 24 dollars. It is divided as shown into smaller and smaller squares. Todd eats every square marked T. If he pays in proportion to the area he eats, how many dollars should he pay? The shrinking pattern is understood to continue without end.