HY's answer to meltedsoups's Secondary 1 Maths Singapore question.
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252 ÷ 18 = 14
Date Posted:
4 years ago
Not true.
LCM of 18 and 14 is 126.
Correct is 28.
LCM of 18 and 14 is 126.
Correct is 28.
What method to use to get that ans?
You have to break them down into their respective constituents first.
18 = 2 x 3^2
252 = 2^2 x 3^2 x 7
The second number needs to contain 2^2 and 7^1 so as to meet the LCM conditions.
(Using 14 = 2 x 7 does not work because it does not provide the essential 2^2 needed for the LCM)
So the second number is 2^2 x 7 = 28.
18 = 2 x 3^2
252 = 2^2 x 3^2 x 7
The second number needs to contain 2^2 and 7^1 so as to meet the LCM conditions.
(Using 14 = 2 x 7 does not work because it does not provide the essential 2^2 needed for the LCM)
So the second number is 2^2 x 7 = 28.
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