## Q&A - PSLE Math

### Re: Q&A - PSLE Math

Hi all,

Posting picture problem on smart phone.

when I post picture using 640x480 and above the picture shown 1/2 of it.

When I use 320x240 it's ok.

Is it my phone problem?

Anybody encounter this problem.

Posting picture problem on smart phone.

when I post picture using 640x480 and above the picture shown 1/2 of it.

When I use 320x240 it's ok.

Is it my phone problem?

Anybody encounter this problem.

### Re: Q&A - PSLE Math

Volume of water in Tank A = 1200t

Tank A base area = 20 X 15 =300 cm2

Therefore height of water in Tank A, Ha = 1200t/300 = 4t

Volume of water in Tank B at first = 20X18X15 = 5400cm3

Drained volume = 720t

Volume 0f water in Tank B left = 5400-720t

Base area of Tank B = 20X18 = 360cm2

Therefore heigh of water in Tank B, Hb = (5400-720t)/360 = 15-2t

a) Condition when both heights are equal, Ha = Hb,

4t=15-2t

15=6t

t=2.5min

b) Height at the point of time = 4(2.5) = 10cm

Tank A base area = 20 X 15 =300 cm2

Therefore height of water in Tank A, Ha = 1200t/300 = 4t

Volume of water in Tank B at first = 20X18X15 = 5400cm3

Drained volume = 720t

Volume 0f water in Tank B left = 5400-720t

Base area of Tank B = 20X18 = 360cm2

Therefore heigh of water in Tank B, Hb = (5400-720t)/360 = 15-2t

a) Condition when both heights are equal, Ha = Hb,

4t=15-2t

15=6t

t=2.5min

b) Height at the point of time = 4(2.5) = 10cm

### Re: Q&A - PSLE Math

Just convert flow rate (litres per minute) to level change rate (cm per minute).

Level change rate for tank A is 1200/20/15 = 4 cm per minute

Level change rate for tank B is 720/18/20 = 2 cm per minute

(a) After t minutes, level of water in A = 4t; level of water in B = 15-2t

Rest just copy Ender's working. I am lazy.

Level change rate for tank A is 1200/20/15 = 4 cm per minute

Level change rate for tank B is 720/18/20 = 2 cm per minute

(a) After t minutes, level of water in A = 4t; level of water in B = 15-2t

Rest just copy Ender's working. I am lazy.

### Re: Q&A - PSLE Math

Amos bought some chickens and gave half of them to Nathan. Nathsn bought some ducks and gave half of them to Amos .

Amos sold 6 ducks and Nathsn sold 9 chickens. In the end the number of ducks Amos had was 1/7 oF the number of his remaining chickens and the number of ducks Nathan had was 1/4 of the number of his remaining chickens .

How many chickens did Amos buy?

How many chickens and ducks did they have altogether in the end ?

Amos sold 6 ducks and Nathsn sold 9 chickens. In the end the number of ducks Amos had was 1/7 oF the number of his remaining chickens and the number of ducks Nathan had was 1/4 of the number of his remaining chickens .

How many chickens did Amos buy?

How many chickens and ducks did they have altogether in the end ?

### Re: Q&A - PSLE Math

At 10.00 am Joash was cycling from Mivo city towards Purmei town. At the same time , Miriam was cycling from Purmei town towards Mivo city on the same route as Joash. Cycling at a speed of 4 km/h faster than MIriam, they would pass each other 400 meters away from the midpoint .

What time did they pass each other?

If Joash took another 4 minutes to reach Purmei town, what time would Miriam reach Mivo city?

What time did they pass each other?

If Joash took another 4 minutes to reach Purmei town, what time would Miriam reach Mivo city?

- Swift Formula
- BlueBelt
**Posts:**246**Joined:**Thu Jun 25,**Total Likes:**2

### Re: Q&A - PSLE Math

It is normal. U just need to click the image for it to blow up.Daddy wrote:Hi all,

Posting picture problem on smart phone.

when I post picture using 640x480 and above the picture shown 1/2 of it.

When I use 320x240 it's ok.

Is it my phone problem?

Anybody encounter this problem.

Preferably Open In New Tab.

Copy Image Location. Ctrl-V to paste in new tab.

This forum auto-crop away part of the picture to display in forums.

Best resolution = Biggest resolution = 1024 pixels in length

Last edited by Swift Formula on Thu Jul 02, 2015 6:55 pm, edited 1 time in total.

- Swift Formula
- BlueBelt
**Posts:**246**Joined:**Thu Jun 25,**Total Likes:**2

### Re: Q&A - PSLE Math

At first Amos and Nathan has the same number of C and D .COOKIE64 wrote:Amos bought some chickens and gave half of them to Nathan. Nathsn bought some ducks and gave half of them to Amos .

Amos sold 6 ducks and Nathsn sold 9 chickens. In the end the number of ducks Amos had was 1/7 oF the number of his remaining chickens and the number of ducks Nathan had was 1/4 of the number of his remaining chickens .

How many chickens did Amos buy?

How many chickens and ducks did they have altogether in the end ?

Amos = D-6 and C

Nathan = D and C-9

7x(D-6) = C

4D = C-9

Using the above 2 equation, do you still need further help?

Last edited by Swift Formula on Thu Jul 02, 2015 7:18 pm, edited 1 time in total.