there is 4 girls for every 1 boy. If we let this be 1grp, then 4+7x4＝32books will be given to each group. So there are 960/32＝30 groups. Hence, there are 30x4＝120 girls.

Any other way to solve this Qn?

I will think of it now. Btw this comparing two equations method is quite common in P6...

mind dealing with decimals?

Hope you can understand Rui Ng and Norlina Tan

Pls chk 30% of 2500 - 40% of 1800.

correct ah 30% of 2500 is 750, 40% of 1800 is 720.

dont scare me leh... took like 45 min to do out the model... 😨

30%A-40%B is 45. Yours is 750 - 720= 30.

oh... crap haha

anyways the approach is the same. lemme redo this...

Your first set is correct for 45 and second set is correct for 30. How about using units and parts? Most P6 know that method.

As B as 45 less students than 3 units of A for every 4 units of B,B will have 22.5 less students than 1.5 units of A for every 2 units of B.45 + 45 + 22.5 + 1 purple unit = 2001 purple unit = 87.5From the first model, 1 purple unit = half a unit of AHalf a unit of A = 87.51 unit of A = 175Since A consists of 10 units, A = 10 x 175 = 175030% of A is 30 more than 40% of B.1750 x 30% - 45 = 40% of B480 = 40% of BB = 480/40% = 1200% of B in A = 1200/1750 x 100% = 68.6% (to 3 sig fig)

Chia-Chan Bk here is my updated version of the ans to this Q. I have also removed my wrong answers.

Im afraid I cant use the units and parts.... I wasnt taught using that when I took my PSLE.

Shu Hao, you r a maths teacher?

Chia-Chan Bk, what is units and parts method?

Rui Ng I am a student 😁

Yueh Mei, just curious. How would you solve this qn?

Rajesh, thanks.

So... is ny first picture (the hand written solution) a form of units and parts?

haha i know its simultaneous eq... but is a simpler version of it... but i nvr knew that wae units and parts 😱

Then units and parts is disguised algebra too... Haha

My model method no algebra! ✌😋✌

Simultaneous equations is not in the syllabus. If units and parts is the only method to solving it, then it is beyond requirement. If you find joy solving the problem, have fun and enjoy it. Do not confuse this with proportional thinking meaning 1 shirt and 2 pants = $10, hence 2 shirts and 4 pants = $20.

For this problem in particular, it is percent in ratio concept. In my opinion, beyond P6 requirement.

Yueh Mei, thanks for clarification. :)

Norlina Tan, can you post your child's school teacher answer after it is given?

According to the syllabus, outcome for percentage is Percentage as part of a whole, percent increase and percent decrease. Percent increase and decrease in comparison with another is not required.

Yueh Mei so you mean cost of 1 pants and 2 shirts is not half of 2 pants and 4 shirts? 😵 dont understand your comment

It is.

Hi all, thanks much for helping! Rui Ng, will post the answer when given.

Norlina Tan, is this qn from the school?

Frankly, I felt that this qn looks more like a sec 1 Maths Qn. I am quite sure some sec 1s may not be able to handle this qn too. Norlina, I am eagerly waiting for teacher's solution.

Yes...

Thank you

haha you want see how a Sec sch student will do this Q? I can show it here! XD

We solve the problem using bar modelling and algebra. The bar A is longer than the bar B. Each bar is divided into 10 equal parts. 3 units of A is 45 more than 4 units of B. After 1 unit of A is given to B, 9 units of A is 200 more than B plus 1 unit of A. 3 units of A = 4 units of B + 45 8 units of A = 10 units of B + 200 We may write: 3u = 4p + 45 8u = 10p + 200 Therefore 15u = 20p + 225 16u = 20p + 400 u = 175 A = 10u = 1750 B = 10p = 1200 B/A = 1300/1750 which is about 69%

This problem is definitely beyond PSLE.

yup. more like a Q from the Gifted Programme...

54 divided by nine times 2

Yes correct but how to explain to my kid?

N model drawing?

Personally, I would not use a model to explain this. I would use a pattern or similar .... but here is a comparison. For the Pattern, you can relate the figure number to the total points.

Ask: how many 9s will give 54? Ans: 54÷9=6 Ask: he needs 2 shots to get 9 points. How many shots does he need to get 6 units of 9 points?

Thks chris...so clear now.

Yueh Mei,im so thkful for this gp.

54?

pardon me I dont understand the model. I dun understand why 3 shorts is equal 2 t shirts

We align the 2 t-shirts and the 3 shorts. The remaining space equals to t shirts and to satisfy the condition of 2 t-shorts and 6 shorts, that made 3 shorts=2 T shirts.

I've the same as Yueh Mei. Explanation is that there are 2 scenarios- same subtotal of $162: Scenario 1: 3 pairs of shorts 2 t shirts and 2 t shirts; or scenario 2: 3 pairs of shorts, 3 pairs of shorts and 2 t shirts Taking out the common items (3 pairs of shorts and 2 t shirts) since same cost then Cost of 2 t shirts = cost of 3 pairs of shorts

thanks

A) no of sqr ＝5x(5+1)＝30 B) no of sqr＝10x(10+1)＝110 C) 156＝12x13 ＝12x(12+1) Hence, the figure number is 12

Thank u.