Lau Guan Yih's answer to Emily's Primary 6 Maths Measurement Singapore question.

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Lau Guan Yih
Lau Guan Yih's answer
59 answers (Tutor Details)
1st
We can form an equation with laptop to get 70% and 30%
So we take 70% - 30% to eliminate the laptop. That will give us the value for 40%