Q&A - PSLE Math

[Michaelia0816]

In a school hall, chairs were arranged in rows such that there were exactly 9 chairs in each row.For a concert, Mr Ong brought 6 more chairs into the school hall and rearranged all the chairs. There are now exactly 7 chairs in each row and 12 more rows than before. How many chairs are there in the school hall for the concert ?


Just for checking,
Is the answer 357?

[Michaelia0816]

tianzhu:

Winx5015:

Hi,


Below are 2011 PSLE math questions, can anyone help to solve?

(1) Nurul and Peili went shopping together with a total sum of $60. Nurul spent twice as much as Peili. the amount Peili had left was $7 more than what she had spent. She had twice as much money left as Nurul.
(a) How much money did Peili spend?
(b) How much money did Nurul have at first?

Hi

For Q1,you may use MD.

Start with the “after” MD.

In the end (money left)
Peili ------ 2 units (boxes) + 7
Nurul ------ 1 unit + 3.5

Now work backwards

In the beginning
Peili ------- 2 units + 2 units + 7
Nurul ------- 4units + 1 unit + 3.5

5 units + 7 + 3.5 ------ 60
5 units ------ 49.5
1 unit ------ 5.5

Peili spent ------- (2*5.5) ------- 11

Nurul -------- (5*5.5) + 3.5 ------ 31

Best wishes

I do not understood, I happened to do this question but somehow Dun know,

How to do backwards and why the 4u is from?

[Michaelia0816]

Help with this question,


(1)Mr Lee baked 185 more chicken pies than tuna pies. After selling 3/5 of the chicken pies and half of the tuna pies, he had 146 pies left. How many pies did he sell?

(2)Mrs Hoon made some cookies to sell. 3/4 of them were chocolate cookies and the rest were almond cookies. After selling 210 almond cookies and 5/6 of the chocolate cookies, she had 1/5 of the cookies left. How many cookies did Mrs Hoon sell?

[2632parent]

Need help on this question, just cannot get the answer?


1) Mr Wu and Mr Zheng travelled along the same expressway to Town M. Mr Wu left his flat at 6.20am and travelled at 90km/h. 40 minutes later, Mr Zheng left for Town M and drove at an average speed of 105 km/h. At what time did they meet on the way?

Thank you

[Michaelia0816]

Em, this is the answer,

4/6*90km=60km
(1h)
Mr Wu----90km+60km=150km
Mr Zheng----105km
…
(4h)
Mr Wu----420km
Mr Zheng----420km

The answer is either at 10.20am or 11am( if include the 40min)

[tianzhu]

Michaelia0816:

Just for checking,
Is the answer 357?

Hi girl

You're correct.

Best wishes

[Michaelia0816]

Add-on:


The "…" I posted just now, it means to do the 2h and the 3h

[Michaelia0816]

Thx!

[Michaelia0816]

Pls help with this question too,


http://t.co/gPLtRATI, sorry to trouble you again!

[tianzhu]

Michaelia0816:

I do not understood, I happened to do this question but somehow Dun know,

How to do backwards and why the 4u is from?

Hi

The amount Peili had left was $7 more than what she had spent.

Spent ------ 2 units

Left ------- 2 units + 7

In the beginning (spent + left)------ 2 units + 2 units + 7

Nurul spent twice as much as Peili

Peili spent 2 units

Hence, Nurul ------ 4 units

Best wishes