Change pack
Lintel Mar 16 - 22 25 questions
PDF (questions) PDF (answers)

Monday 16 March 2026

Keystones #75 · Five questions · Open this day only

  1. 1. Number

    A value is 49.2 (to dp). State the error interval

    Answer: 49.15 ≤ x < 49.25
  2. 2. Algebra

    Expand: (x - 6)(x - 3)

    Answer: x² - 9x + 18
  3. 3. Geometry

    A circle has area 78.5cm². Find its radius (dp)

    Answer: 5cm
  4. 4. Ratio

    Express 26 as a percentage of 232

    Answer: 11.21%
  5. 5. Statistics

    Find the mean, mode, median and range of: 26, 26, 30, 10, 44

    Answer: Mean = 27.2, Mode = 26, Median = 26, Range = 34

Tuesday 17 March 2026

Keystones #76 · Five questions · Open this day only

  1. 1. Number

    30 is rounded to the nearest integer. What is the error interval?

    Answer: 29.5 ≤ x < 30.5
  2. 2. Algebra

    Expand: (x + 6)(x - 2)

    Answer: x² + 4x - 12
  3. 3. Geometry

    Calculate the area of a circle with diameter 15cm

    Answer: 176.71cm²
  4. 4. Ratio

    Express 66 as a percentage of 102

    Answer: 64.71%
  5. 5. Statistics

    Find the mean, median and range of: 65, 83, 93, 34, 66, 68, 14

    Answer: Mean = 60.4, Median = 66, Range = 79

Wednesday 18 March 2026

Keystones #77 · Five questions · Open this day only

  1. 1. Number

    22 is rounded to the nearest integer. What is the error interval?

    Answer: 21.5 ≤ x < 22.5
  2. 2. Algebra

    Expand: (x + 7)(x - 6)

    Answer: x² + x - 42
  3. 3. Geometry

    Calculate the area of a circle with diameter 13cm

    Answer: 132.73cm²
  4. 4. Ratio

    Express 65 as a percentage of 209

    Answer: 31.1%
  5. 5. Statistics

    Find the mean, median and range of: 78, 18, 89, 93, 42, 93, 50, 35, 76

    Answer: Mean = 63.8, Median = 76, Range = 75

Thursday 19 March 2026

Keystones #78 · Five questions · Open this day only

  1. 1. Number

    A value is 99.2 (to dp). State the error interval

    Answer: 99.15 ≤ x < 99.25
  2. 2. Algebra

    Expand: (x - 6)(x - 7)

    Answer: x² - 13x + 42
  3. 3. Geometry

    A circle has area 452.4cm². Find its radius (dp)

    Answer: 12cm
  4. 4. Ratio

    Express 39 as a percentage of 180

    Answer: 21.67%
  5. 5. Statistics

    Find the mean, mode, median and range of: 32, 22, 45, 22, 11

    Answer: Mean = 26.4, Mode = 22, Median = 22, Range = 34

Friday 20 March 2026

Keystones #79 · Five questions · Open this day only

  1. 1. Number

    25 is rounded to the nearest integer. What is the error interval?

    Answer: 24.5 ≤ x < 25.5
  2. 2. Algebra

    Expand: (x - 4)(x - 3)

    Answer: x² - 7x + 12
  3. 3. Geometry

    Calculate the area of a circle with diameter 19cm

    Answer: 283.53cm²
  4. 4. Ratio

    Express 69 as a percentage of 186

    Answer: 37.1%
  5. 5. Statistics

    Find the mean, median and range of: 58, 62, 24, 73, 74, 10, 90, 63

    Answer: Mean = 56.8, Median = 63, Range = 80