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2022 Beaver Computing Challenge
(Grade 5 & 6)

Questions

Part A

Beaver Children

Story

A beaver family has five children with different heights as shown.

The children, in order from shortest to tallest, are as follows: Qadr, Ravi, Todd, Sana, Peng.

The two tallest children and two shortest children leave.

Question

Which child remains?

  1. Qadr
  2. Ravi
  3. Sana
  4. Todd

Trail Home

Story

In between a beaver and her home are some trails, where each intersection is marked with a different tree. The beaver walks home using these trails passing exactly four intersections on the way.

A description of the diagram follows.

Question

In which order could the beaver have passed the intersections?

Hamburger Recipe

Story

A hamburger is made using the following six ingredients.

Bun Meat Sauce Lettuce Onions Cheese

The hamburger is made according to the following three rules.

  1. The sauce should be directly on top of the meat.

  2. The meat and cheese should be somewhere below the lettuce and onions.

  3. The onions should not be in contact with the bun.

Question

Which of the following could be the hamburger?

  1. The ingredients on top of the bottom bun, listed from bottom to top, are cheese, meat, sauce, lettuce, onions.
  2. The ingredients on top of the bottom bun, listed from bottom to top, are meat, sauce, lettuce, onions, cheese.
  3. The ingredients on top of the bottom bun, listed from bottom to top, are meat, cheese, sauce, onions, lettuce.
  4. The ingredients on top of the bottom bun, listed from bottom to top, are meat, sauce, cheese, onions, lettuce.

Lila’s Guessing Game

Story

Lila and her friends play a guessing game. To start, Lila puts a marble in bag X, a gem in bag Y, and a crumpled piece of paper in bag Z.

Then, while her friends' eyes are closed, she mixes up the contents of the bags.

  1. First, she switches the items in bags X and Y.

  2. Then, she switches the items in bags X and Z.

  3. Finally, she switches the items in bags Y and Z.

Question

Where are Lila’s items now?

  1. The marble is in bag X, the paper is in bag Y, and the gem is in bag Z.
  2. The paper is in bag X, the gem is in bag Y, and the marble is in bag Z.
  3. The gem is in bag X, the paper is in bag Y, and the marble is in bag Z.
  4. The paper is in bag X, the marble is in bag Y, and the gem is in bag Z.

Part B

Remembering Faces

Story

Talia is very forgetful, so she has created a system to help her remember the names of her four group members.

If a group member is wearing sunglasses, Talia checks to see if they are wearing a hat. If they are wearing a hat, then it is Ash, otherwise it is Deniz. If the group member is not wearing sunglasses, Talia checks to see if they are wearing a scarf. If they are wearing a scarf, then it is Raul, otherwise it is Ming.

A decision tree.

Question

Which of the following correctly matches names with faces?

  1. Ash is wearing sunglasses and a hat. Deniz is wearing sunglasses. Raul is wearing a scarf. Ming is not wearing any of the items.
  2. Ash is wearing sunglasses and a hat. Deniz is wearing sunglasses. Raul is not wearing any of the items. Ming is wearing a scarf.
  3. Ash is wearing sunglasses. Deniz is not wearing any of the items. Raul is wearing a scarf. Ming is wearing sunglasses and a hat.
  4. Ash is wearing sunglasses and a hat. Deniz is wearing a scarf. Raul is wearing sunglasses. Ming is not wearing any of the items.

Colourful Tower

Story

Luis has hexagon pieces in three different colours. Whenever Luis arranges three pieces in a way that resembles an upright triangle, the three pieces must either be all the same colour, or all different colours. These rules do not apply to other three-piece arrangements. In particular:

All colours the same
or all colours different
Three identical regular hexagons placed so they have two vertical sides, two angled top sides, and two angled bottom sides. Two hexagons, placed side-by-side, form a bottom row. A third hexagon is placed on top so that it shares an edge with each of the bottom hexagons.

No colour rules
Two hexagons, placed side-by-side, form a top row. A third hexagon is placed on the bottom so that it shares an edge with each of the top hexagons.

Luis arranges his hexagon pieces in a way that resembles a tower as shown:

A description of the tower follows.

Question

Which hexagon piece must be at the very top?

  1. blue hexagon
  2. green hexagon
  3. yellow hexagon
  4. There is more than one possibility

Apples, Bananas, Broccoli, and Carrots

Story

Some fruit (apples and bananas), and some vegetables (broccoli and carrots) are placed on four plates:

The first plate has one banana. The second plate has one apple, one banana, one broccoli, and one carrot. The third plate has one broccoli and one carrot. The fourth plate has one apple, one banana, and one carrot.

Then the following actions are performed, in the order given:

  1. One banana is added to each plate.

  2. Each plate with less than four items in total, is removed.

  3. All the fruit is removed from each plate.

  4. Each plate with at least one carrot and no other fruit or vegetables, is removed.

Question

How many plates remain after all the actions are performed?

  1. 0
  2. 1
  3. 2
  4. 3

Tortoise and Hare

Story

A tortoise and a hare follow the arrows in the diagram shown.

A description of the diagram follows.

They both start at the same time at the circle labelled with a heart. The tortoise moves from one circle to the next in two minutes. The hare moves from one circle to the next in one minute.

Question

Where do the tortoise and hare meet for the first time after they begin moving?

  1. watermelon
  2. acorn
  3. orange
  4. garlic

Part C

Spring Blossom

Story

Janine is planting a row of seven flowers in her flowerbed. She has the following types of flowers.

Tulip Daffodil Pansy Snowdrop

She plants her flowers in her flowerbed according to the following plan.

  1. The flowers must be planted in a row from left to right.

  2. Any flower can be planted in the leftmost spot.

  3. Two flowers can be planted next to each other only if the diagram shows an arrow from the flower being planted first to the flower being planted next.

    A description of the diagram follows.

For example, Janine can plant a tulip and then a daffodil to its right because there is an arrow from the tulip to the daffodil. However, she cannot plant a daffodil and then a tulip to its right because there is no arrow from the daffodil to the tulip.

Question

Which flowerbed could not possibly be Janine’s?

  1. From left to right, the planted flowers are tulip, daffodil, snowdrop, daffodil, pansy, pansy, pansy.
  2. From left to right, the planted flowers are snowdrop, daffodil, pansy, tulip, daffodil, pansy, pansy.
  3. From left to right, the planted flowers are tulip, daffodil, snowdrop, tulip, daffodil, pansy, pansy.
  4. From left to right, the planted flowers are daffodil, snowdrop, daffodil, snowdrop, tulip, daffodil, snowdrop.

Hide and Seek

Story

Four of Gosia’s friends are hiding in a park. No two friends are hiding in the same spot. Gosia knows the following information about who is hiding where:

Question

What is Rona hiding behind?

  1. The trees
  2. The fountain
  3. The bench
  4. The lamppost

Beach Necklaces

Story

Bashir makes necklaces using wavy beads and blue beads. He always makes them as follows.

  1. Place one wavy bead and one blue bead on a string with the wavy bead to the left of the blue bead.

  2. Do one of the following two actions.

    Starting with a string with a wavy bead on the left and a blue bead on the right, applying action B results in a string with the following beads from left to right: blue, wavy, blue, blue. If instead action W is applied, the result is a string with the following beads: wavy, blue, wavy, wavy.

  3. Repeat step 2 until the necklace is complete.

Question

Which necklace below cannot be made by Bashir?

  1. From left to right the beads are 1 blue, 1 wavy, 2 blue, 4 wavy.
  2. From left to right the beads are 2 blue, 1 wavy, 3 blue, 2 wavy.
  3. From left to right the beads are 1 blue, 1 wavy, 1 blue, 2 wavy, 1 blue, 2 wavy.
  4. From left to right the beads are 1 blue, 1 wavy, 3 blue, 3 wavy.

Strawberry Patch

Story

Every day, a beaver goes to a strawberry patch for dessert. It starts eating strawberries from one of the twelve fields in the patch. Then it moves either north (\(\uparrow\)), south (\(\downarrow\)), east (\(\rightarrow\)), or west (\(\leftarrow\)) to a neighbouring field exactly three times.

This behaviour ensures that the beaver eats strawberries from exactly four fields and leaves the rest of the strawberries for others to enjoy.

For example, in the strawberry patch shown, a beaver could follow the path shown on the left and eat \(1+1+7+5=14\) strawberries or follow the path shown on the right and eat \(6+9+1+8=24\) strawberries.

Four fields are visited by walking north, then west, then south. The fields had 1, 1, 7, and 5 strawberries.

Four fields are visited by walking east, then north, then north again. The fields had 6, 9, 1, and 8 strawberries.

Question

What is the maximum number of strawberries the beaver could eat from the following patch?

A description of the strawberry patch follows.

  1. 21
  2. 22
  3. 23
  4. 24