How to Split a 3-Hour Exam: CBSE Time Plan by Section

Three hours feels like a lot of time until you are on question 30 with forty minutes left. The fix is a plan made before you write a word: a time to finish each section by, worked out from its marks. Here is how to make one, with two CBSE papers worked through in full.

The rule: time follows marks

A section worth a quarter of the marks gets a quarter of the time. To put numbers on that:

Keep some time at the end for checking. Fifteen minutes is common advice for a 3-hour paper; it is your choice, not a board rule.
Divide what is left by the total marks. That is your minutes per mark.
Multiply each section’s marks by it, and add the times up from the start.

On a CBSE paper, writing runs from 10:30 to 1:30. Keeping 15 minutes for checking leaves 165 minutes for answering, so an 80-mark paper gets 2.06 minutes a mark, and a 70-mark paper 2.36.

The 15 minutes of reading from 10:15 is extra: no writing is allowed, and it does not come out of the three hours. Use it to read every question, settle your internal choices, and write the finish-by times at the top of your rough sheet.

Class 10 Mathematics (Standard): 80 marks

CBSE’s 2025-26 sample paper for Mathematics Standard has 38 questions in five sections: 20 one-mark questions in A, five 2-mark questions in B, six 3-mark questions in C, four 5-mark questions in D and three 4-mark case studies in E.

Section	Marks	Time	Each question	Finish by
A (MCQ, 1 mark)	20	41 min 15 s	2 min 4 s	11:11
B (2 marks)	10	20 min 38 s	4 min 8 s	11:31
C (3 marks)	18	37 min 8 s	6 min 11 s	12:09
D (5 marks)	20	41 min 15 s	10 min 19 s	12:50
E (case study, 4 marks)	12	24 min 45 s	8 min 15 s	1:15
Checking		15 min		1:30

Finish-by times are rounded down to the minute, so the plan runs a little early rather than late.

Section A is the trap. Twenty MCQs feel quick, and many are, but the plan gives them 41 minutes because they carry a quarter of the marks. If you finish them in 25, you have 16 minutes in hand for Section D, where a single question is worth five.

If you would rather not keep checking time, the same paper with all 3 hours shared out gives 2.25 minutes a mark, and the finish-by times become 11:15, 11:37, 12:18, 1:03 and 1:30.

Class 12 Physics: 70 marks

Physics has 30 marks for practicals, so the theory paper is out of 70 in the same 3 hours. CBSE’s 2025-26 sample paper has 33 questions: sixteen 1-mark questions in A (multiple choice and assertion-reason), five 2-mark questions in B, seven 3-mark questions in C, two 4-mark case studies in D and three 5-mark long answers in E.

Section	Marks	Time	Each question	Finish by
A (MCQ and A-R, 1 mark)	16	37 min 43 s	2 min 21 s	11:07
B (2 marks)	10	23 min 34 s	4 min 43 s	11:31
C (3 marks)	21	49 min 30 s	7 min 4 s	12:20
D (case study, 4 marks)	8	18 min 51 s	9 min 26 s	12:39
E (5 marks)	15	35 min 21 s	11 min 47 s	1:15
Checking		15 min		1:30

With fewer marks in the same time, every mark gets more: 2.36 minutes against 2.06 on an 80-mark paper. Section C is the longest stretch, nearly 50 minutes, so it is the one to check the clock in the middle of.

Your own paper

Other subjects split their marks differently, and the board can change a pattern from one year to the next, so check the general instructions on your own sample paper. The exam time calculator has the two papers above as presets and lets you type your own sections. Give each row its marks and number of questions, type the start time, and it prints the same kind of table, ready to keep beside you.

Taking sections out of order

Unless your paper’s instructions say otherwise, you can choose the order you answer in, numbering each answer clearly, and some students start with the long answers while they are fresh. The time each section gets does not change. Only the clock times shift, so make the plan in the order you will actually work: add the sections to the calculator in that order and the finish-by times follow.

Practise to the plan

A plan you have never used is a guess. In each mock paper, run the exam clock for 3 hours with 15 minutes of reading first, and note at the end of every section whether you were ahead of or behind your finish-by time. Two or three papers in, you will know which section you overrun, and you can move minutes to it before the day.

For the invigilator’s side of the same three hours, see how to time an exam.

Questions people ask

How should I divide time in a 3-hour CBSE exam?

Use the 15 minutes of reading to plan. Keep about 15 minutes at the end for checking. Share the remaining 2 hours 45 minutes out by marks: 2.06 minutes a mark on an 80-mark paper, 2.36 on a 70-mark paper. Write down the time each section should be finished by.

How much time for each section in CBSE Class 10 Maths?

With 15 minutes kept for checking: Section A about 41 minutes, B about 21, C about 37, D about 41 and E about 25. Starting at 10:30, finish A by 11:11, B by 11:31, C by 12:09, D by 12:50 and E by 1:15, then check until 1:30.

How much time per question in CBSE Class 12 Physics?

With 15 minutes kept for checking, about 2 minutes 21 seconds for a 1-mark question, 4 minutes 43 seconds for 2 marks, 7 minutes 4 seconds for 3 marks, 9 minutes 26 seconds for a 4-mark case study and 11 minutes 47 seconds for a 5-mark long answer.

Should I answer the sections in order?

Unless your paper's instructions say otherwise, you can choose an order that suits you, numbering each answer clearly; some students do the long answers while they are fresh. The time for each section stays the same whatever order you take them in; only the clock times move.

Is the 15-minute reading time part of the 3 hours?

No. In CBSE board exams the paper is handed out at 10:15 for 15 minutes of reading, with no writing allowed, and the 3 hours of writing run from 10:30 to 1:30.

How to split a 3-hour exam: a section-by-section time plan for CBSE papers

The short answer