Matrices
NCERT Class 12
CBSE
Grade 12
Question:
If a matrix has $18$ elements, what are the possible orders it can have?
(a) $1 \times 18, 2 \times 9, 3 \times 6, 6 \times 3, 9 \times 2, 18 \times 1$
(b) $1 \times 18, 2 \times 9, 3 \times 6$
(c) $2 \times 9, 3 \times 6, 6 \times 3, 9 \times 2$
(d) $1 \times 18, 18 \times 1$
Step-by-Step Solution
Pairs $(m, k)$ such that $m \cdot k = 18$: $(1,18), (2,9), (3,6), (6,3), (9,2), (18,1)$. [1.0 Mark]
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🎯 Official CBSE Marking Scheme:
Selecting all 6 factor pair orders: 1.0 Mark
Correct Answer: $1 \times 18, 2 \times 9, 3 \times 6, 6 \times 3, 9 \times 2, 18 \times 1$
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