O/L past papers › 2020

O/L Maths 2020 Paper

English medium · held March 2021 (cover shows no date; exam delayed by COVID-19)

All 42 questions from Paper I and Paper II, with what each one tests. Try any of them free in Gedara Sir to check your answer, with step-by-step working.

Most marks in 2020 came from

Paper I, Part A

Paper I Part A Q1 · 2 marks

Percentages

VAT percentage from the tax added to a bill

Paper I Part A Q1: VAT percentage from the tax added to a bill

Answer: 12%

💡 What it's asking: We want to know what percent Rs 180 is of Rs 1500, the bill before tax.

  1. 1Write it as a fraction: 180/1500.
  2. 2Turn it into a percent: × 100.
  3. 3180 ÷ 1500 × 100 = 12%.

✅ 12% of 1500 = 180, so it matches.

සිංහලෙන් විසඳුම

රු. 1500 (බද්දට පෙර බිල) න් රු. 180 කොපමණ ප්‍රතිශතයක්ද යන්න සොයමු.

  1. භාගයක් ලෙස ලියන්න: 180/1500.
  2. ප්‍රතිශතයක් කරන්න: × 100.
  3. ගණනය: 180 ÷ 1500 × 100 = 12%.

Paper I Part A Q2 · 2 marks

Triangles

Base angle of an isosceles triangle from an exterior angle

Paper I Part A Q2: Base angle of an isosceles triangle from an exterior angle

Answer: x = 70

💡 What it's asking: Turn the outside angle into the inside angle, then use the equal base angles.

  1. 1Inside angle at C = 180° − 110° = 70° (straight line).
  2. 2The marked equal sides make the two bottom angles equal.
  3. 3So x = 70.

✅ Top angle = 180 − 70 − 70 = 40°, a sensible positive angle.

සිංහලෙන් විසඳුම

පිටත කෝණය ඇතුළත කෝණයට හරවා සමාන ආධාරක කෝණ යොදන්න.

  1. C හි ඇතුළත කෝණය = 180° − 110° = 70° (සරල රේඛාව).
  2. ලකුණු කළ සමාන පාද නිසා පහළ කෝණ දෙක සමානයි.
  3. එබැවින් x = 70.

Paper I, Part B

Paper II, Part A

Paper II, Part B