CBSE Class 10 Mathematics Basic 2026: question 2
Set in the CBSE Class 10 board exam of 2026, paper 430/3/1, section A, question 2, for 1 mark. Try it first; the hints and our step-by-step solution are below.
Q2 · 1 mark · MCQReal Numbers
, where n is a natural number, cannot end with the digit:
- (A)3
- (B)5
- (C)7
- (D)9
Source: official question paper from cbse.gov.in (PDF). See it in the full 2026 board paper, set 430/3/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
Work out and look at their last digits.
Hint 2
A number ending in 5 must be divisible by 5.
Step-by-step solution
Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.
The last digits of repeat in the cycle 3, 9, 7, 1.
- 1 mark
To end in 5 a number needs 5 as a prime factor, but has only the prime factor 3. So cannot end in 5.
Answer: 5, option (B)
Where the marks are
- Identifies that 5 is not a factor of , so the last digit cannot be 5 (1 mark)
Revise the chapter
- Chapter: Real Numbers (notes, formulas, where marks are lost and every past question)
- Topic: Fundamental Theorem of Arithmetic
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The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.