In which of the following expressions, prime factorisation has been done?
(a) $ 24=2 \times 3 \times 4 $
(b) $56 = 7 \times 2 \times 2 \times 2$
(c) $70 = 2 \times 5 \times 7$
(d) $54 = 2 \times 3 \times 9$

AcademicMathematicsNCERTClass 6

To do:

We have to find whether the prime factorisation has been done in each of the given cases.

Solution:

(a) $24=2\times12$

$=2\times3\times4$

$=2\times3\times2\times2$

Prime factorisation of 24 is,

$24=2\times3\times2\times2$

Hence, the prime factorisation has not been done.

(b) $56=2\times28$

$=2\times2\times14$

$=2\times2\times2\times7$

Prime factorisation of 24 is,

$56=2\times2\times2\times7$

Hence, the prime factorisation has been done.

(c) $70=2\times35$

$=2\times5\times7$

Prime factorisation of 70 is,

$70=2\times5\times7$

Hence, the prime factorisation has been done. 

(d) $54=2\times27$

$=2\times3\times9$

$=2\times3\times3\times3$

Prime factorisation of 54 is,

$54=2\times3\times3\times3$

Hence, the prime factorisation has not been done. 

raja
Updated on 10-Oct-2022 13:30:36

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