Q&A - PSLE Math

[tianzhu]

Hi small


Good Morning.

You’ll get an answer in decimals.

Cake: cream puffs ------ 2 units: 1 unit
Cake: cream puffs ----- -90: -42
Cake: cream puffs ------ 2 parts: 5 parts

Cross multiply or equalising the parts

10 units – 450 ------ 2 units – 84
8 units ------- 366
1 unit ------- 45.75

Hence, you’ll end up with 3*45.75 or 137.25 cakes and cream puffs at first.(not in whole number)

Best wishes

[small]

Good morning tianzhu,


We also got 8U = 366, my DS said may be somebody ate the cake and puff..

[MathIzzzFun]

small:

Good morning tianzhu,


We also got 8U = 366, my DS said may be somebody ate the cake and puff..

good morning!

haha.. I think the question was likely adapted by changing only names of items - if the cakes and puffs are replaced by kg of flour and kg of sugar, then the answer will make sense

[YumYum]

Hi small,


Thank you for the 2 methods to derive the answers.

Your child is ahead of mine in practising the papers

have a good week-end!

[small]

U r welcome YumYum

[tianzhu]

insider:

deleted to avoid confusion.


Tireless Tianzhu, thank you!

Hi insider

Good Morning.

I am surprised you’re looking at the solutions because I understand you have grown up children.

Once again, thank you.

Best wishes

[homeworkmummy]

Hi, pls help with the following question and thanks in advance.


Xavier, Yew Ming and Zason bought a watch for their mother on her birthday. Xavier paid 1/4 of what Yew Ming and Zason paid. Yew Ming paid 1/5 of what Xavier and Zason paid. If Zason paid $56 more than Yew Ming, how much did the watch cost?

[tianzhu]

homeworkmummy:

Hi, pls help with the following question and thanks in advance.


Xavier, Yew Ming and Zason bought a watch for their mother on her birthday. Xavier paid 1/4 of what Yew Ming and Zason paid. Yew Ming paid 1/5 of what Xavier and Zason paid. If Zason paid $56 more than Yew Ming, how much did the watch cost?

Hi

You may work using UM or MD.

X : (YM + Z) ------ 1:4 ------- 5 (total)
YM: (X+Z) ------ 1:5 ------- 6 (total)

Common multiple of 5 and 6 ------ 30

X : (YM + Z) ------ 6:24 ------- 30 (total)
YM: (X+Z) ------ 5:25 ------- 30 (total)

YM ----- 5 units
X ------ 6 units
Z ----- 19 units

19 – 5 ----- 14

14 units ----- 56
1 unit ------ 4

30 units ------ 30*4 ------- 120(cost of watch)

Best wishes

[millan]

Pls help to solve this:


The ratio of no of 20cents coinys to the no of 1 dollar coins in a container was 1:4 . 6 1 dollar coins were taken out of the container and exchanged foe 20 cent coin which were put into the container. The ratio of the no of 20 cents coins to the no of 1 dollar coin became 3:5 . How much money was there in the container.

We got $100.8 (ans not known yet) by algebra, qn is can this be solved by model?

Thks

[tianzhu]

millan:

Pls help to solve this:


The ratio of no of 20cents coinys to the no of 1 dollar coins in a container was 1:4 . 6 1 dollar coins were taken out of the container and exchanged foe 20 cent coin which were put into the container. The ratio of the no of 20 cents coins to the no of 1 dollar coin became 3:5 . How much money was there in the container.

We got $100.8 (ans not known yet) by algebra, qn is can this be solved by model?

Thks

Hi

Good Morning.

I did a quick check and the answer is $100.80.

You may work out this question from two perspectives, one in term of numbers of coins and dollar notes and the other in term of the value of money.

There are some similar types of questions in earlier posts in this thread.

Yes, you may use MD, Units and Parts or Systematic Listing.

Best wishes