Kenta Philip Endo's answer to KK ng's Primary 5 Maths Percentage Singapore question.

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Kenta Philip Endo
Kenta Philip Endo's answer
5 answers (Tutor Details)
Hi there! Wow, this question is pretty tough, but I hope this helps:) I think drawing a model really helps with this question since it helps you visualise the fraction of coins used. Most important thing would be to realise that the number of 20 cent coins used and left are the same, since 50% of 20 cent coins are used. So any difference in the number of coins after would come from the difference in 50 cent coins. Do let me know if this helped!
KK ng
KK Ng
2 years ago
Thanks. But seems like not correct. A should be 30% and b is $8.60.
J
J
2 years ago
Not correct.

12 coins represent 50% of the 50¢ coins, not 25%. See main question's comments section for my working.