Thank you all for your help!

This diagram represents the information given. See if you can work backwards from the $76 to get the answer. To start off, 76+20 represents 3 units, so what would 5 units be? Then continue from there...

This diagram should help you start. The next question to ask is how to subdivide from the remaining fourths and fifths so that we can equate a certain number of equal units to 120 (essentially looking for LCM). Try and see if you can work it out from here....

S: 2/5 = 8/20 A: 1/4 = 5/20 The diff is 3units and 120stickers 1 unit: 120/3= 40stickers Total 20units:40x20=800stickers

Sorry my above working was wrong. 😆

Vei Li Soo,Wilson Lim Wee Sheng,Tjew Sheng Wei Thank you.

Using Guess n Check.... 13 Red 7 White

here you go

Can use?

Hi Alex R. S. Chia... From my understanding.. They will accept this working at the PSLE... But at that age.. I'm not so sure about the understanding of the subject matter on the part of the students

There is more than 1 answer, right?

Only 1 answer

Ok, thank you everyone! I finally got it.

There is only 1 answer Linda Tay... However as demonstrated.. There are more than just a few ways to work out the answer ☺

Welcome

If using guess and check: due to the $5 and $2 costs, and total cost with unit digit 9 ($79), we know the cost of plates must have a unit digit 4 (so $4 or $14). This makes the guessing less random.

Answer ☺️

Alex R. S. Chia,KH Puah Thank you.

Total age 5years ago: 82-10 =72 years Thus: Mrs Lim 5units + 1unit for son = 6units 1unit: 72years/6 = Now: 12yrs +5 old for son Now: 60yrs +5 old for Mrs Lim.

Wilson Lim Wee Sheng Thank you