Change pack
Lintel Apr 27 - May 3 25 questions
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Monday 27 April 2026

Keystones #117 · Five questions · Open this day only

  1. 1. Number

    Express 100 as a product of prime factors

    Answer: 2² × 5²
  2. 2. Algebra

    Solve: 2x + 3y = 20 and 3x - y = 19

    Answer: x = 7, y = 2
  3. 3. Geometry

    Find b if a = 13cm and c = 21cm

    Answer: 16.49cm
  4. 4. Ratio

    a:b is 2:3 and b:c is 4:3. Find a:b:c.

    Answer: 8:12:9
  5. 5. Statistics

    A fair coin is flipped 186 times. How many heads would you expect?

    Answer: 93

Tuesday 28 April 2026

Keystones #118 · Five questions · Open this day only

  1. 1. Number

    Express 200 as a product of prime factors

    Answer: 2³ × 5²
  2. 2. Algebra

    Solve: 2x + 3y = 30 and 3x - y = 12

    Answer: x = 6, y = 6
  3. 3. Geometry

    Find b if a = 15cm and c = 25cm

    Answer: 20cm
  4. 4. Ratio

    a:b is 3:4 and b:c is 1:2. Find a:b:c.

    Answer: 3:4:8
  5. 5. Statistics

    A fair coin is flipped 120 times. How many heads would you expect?

    Answer: 60

Wednesday 29 April 2026

Keystones #119 · Five questions · Open this day only

  1. 1. Number

    Write 72 as a product of its prime factors

    Answer: 2³ × 3²
  2. 2. Algebra

    Solve: 4x + 3y = 38 and 3x + 3y = 30

    Answer: x = 8, y = 2
  3. 3. Geometry

    Calculate the missing side: a = 24cm, c = 29cm

    Answer: 16.3cm
  4. 4. Ratio

    a:b is 3:2 and b:c is 1:2. Find a:b:c.

    Answer: 9:6:12
  5. 5. Statistics

    A bag has 3 red out of 12 balls. If you pick 54 times (with replacement), how many times would you expect red?

    Answer: 13.5

Thursday 30 April 2026

Keystones #120 · Five questions · Open this day only

  1. 1. Number

    Write 90 as a product of its prime factors

    Answer: 2 × 3² × 5
  2. 2. Algebra

    Solve: 2x + 3y = 12 and 4x + 4y = 20

    Answer: x = 3, y = 2
  3. 3. Geometry

    Find b if a = 11cm and c = 19cm

    Answer: 15.49cm
  4. 4. Ratio

    a:b is 2:1 and b:c is 4:5. Find a:b:c.

    Answer: 8:4:5
  5. 5. Statistics

    A bag has 4 red out of 11 balls. If you pick 78 times (with replacement), how many times would you expect red?

    Answer: 28.4

Friday 1 May 2026

Keystones #121 · Five questions · Open this day only

  1. 1. Number

    Express 180 as a product of prime factors

    Answer: 2² × 3² × 5
  2. 2. Algebra

    Solve: 2x + 3y = 22 and 3x - y = 22

    Answer: x = 8, y = 2
  3. 3. Geometry

    Calculate the missing side: a = 22cm, c = 40cm

    Answer: 33.4cm
  4. 4. Ratio

    a:b is 2:3 and b:c is 1:3. Find a:b:c.

    Answer: 4:6:18
  5. 5. Statistics

    A bag has 4 red out of 12 balls. If you pick 132 times (with replacement), how many times would you expect red?

    Answer: 44