Kuala Lumpur Trial 2025 Add Maths Paper 1, Question 13Indices, Surds & Logarithms

Solved on video in English · Form 4, Indices, Surds & Logarithms · 5:49 video

The question

(a)

Ali is solving a math puzzle. He finds a mysterious note that says: "To unlock the treasure box, you must solve this riddle: The logarithm base five of the sum of a number with one is equal to four-thirds plus the logarithm base one hundred twenty-five of the sum of that number with one." What is the possible number Ali should use to unlock the treasure?

(b)

Aiman wants to produce a transparent cuboid container for a model of a traditional house. The dimensions of the container are as shown in Diagram 8: length x cm, width 4 cm and height (5 − √7) cm. If the volume of the container is 52√7 − 44, find the value of x in the form a + √b.

Kuala Lumpur Trial 2025 Add Maths Paper 1, Question 13: the question as drawn in Eduly's video5:49

Part (a)

Step 1

Let the number be x. The riddle states log₅(x + 1) = 4/3 + log₁₂₅(x + 1).

3 more steps, each with the reason for it, in the full solution

Final answer

x = 24

Where students lose marks

Watch out: convert log₁₂₅ to base 5 first, and remember to subtract 1 from x + 1 = 25 to get x.

Part (b)

4 more steps, each with the reason for it, in the full solution

Final answer

x = 2 + 3√7 (a = 2, b = 63)

Watch every step of this question solved on video (5:49), with the reason behind each step and a box that checks your own answer.

Start 7 days freeAlready a member? Watch it now

No card. Every past-year question on video, in English and BM.

All questions in Kuala Lumpur Trial 2025 Paper 1

Indices, Surds & Logarithms: lessons and every past-year question

More Indices, Surds & Logarithms questions

Questions are re-typeset by Eduly for study and commentary. Eduly is not affiliated with Lembaga Peperiksaan Malaysia or the Ministry of Education.