Tutor MathsGuru: Ask me for your burning Maths questions!

[YLH88]

Hi Vanilla Cake, speedmaths.com


Thanks for the solution!!

[Vanilla Cake]

YLH88:

Hi Vanilla Cake,


I'm not able to draw the 1st diagram from Nanyang paper, also I do not have a scanner at home, so can't post the diagram. Any one able to help ? The diagram sure looks complicated

But I managed to draw the 2 diagrams from Maha Bodhi questions and uploaded here for reference :

2) Maha Bodhi School P6 Prelim 2010 Maths paper 2 Q15

http://www.postimage.org/image.php?v=aVy7AiA

3) Maha Bodhi School P6 Prelim 2010 Maths paper 2 Q18

http://www.postimage.org/image.php?v=aVy7MMi

Hi YLH88,
Thks for your time and effort. Good news! Some of these P6 Prelim 2010 Maths questions from top schools had been answered by http://www.kiasuparents.com/kiasu/forum/viewtopic.php?t=280&postdays=0&postorder=asc&start=1680 from page 169 onwards and http://psle2010a.blogspot.com/.

Hi Uncle Tianzhu/Uncle Observer,
I hope that both of you are reading my message. I want to say a big thank you for your time and effort in helping P6 students and upcoming P6 students (My P5 younger sister) in handling the dreadful cum fearful PSLE Maths exams.

[little_twin_stars]

Dear all, pls help me to understand this qn…


TIA.


20% of John’s savings was $120 more than 30% of Brian’s savings. After John spent 5/6 of his savings and Brian spent 1/6 of his savings, John had $20 more than Brian. Find the savings of John at first.


Although I have the answer key… I cannot understand how it worked out.

Pls help… Thank you very veyr much

[Dharma]

little_twin_stars:

Dear all, pls help me to understand this qn....


TIA.


20% of John's savings was $120 more than 30% of Brian's savings. After John spent 5/6 of his savings and Brian spent 1/6 of his savings, John had $20 more than Brian. Find the savings of John at first.


Although I have the answer key... I cannot understand how it worked out.

Pls help... Thank you very veyr much

John’s savings = 30u
Brian’s savings = 30p

20% of 30u = 30% of 30p + $120
6u = 9p + $120 ------------- ( 1 )

(5/6 x 30u) – (1/6 x 30p) = $20
25u – 5p = $20 -------------- (2)

You have 2 equations and 2 unknowns; you can solve the qn

John’s savings ate first = 30u = 30 x ?

[little_twin_stars]

Thanks…


but call me dumb, ignorant… but why 30u and 30p?

The simultaneously equation part I understand liao… but

haiz…

help …

[Dharma]

little_twin_stars:

Thanks...


but call me dumb, ignorant... but why 30u and 30p?

The simultaneously equation part I understand liao... but

haiz...

help ...

Wanted to avoid decimals when it comes to multiply by 20%, 30% or even the fractions. So, I try to make life easy.

You can use 6u & 6p or any of its multiples…. No problem.

[little_twin_stars]

okay, i understood already...


thanks a lot

[Carrot]

Hi thank you in advance please help me stuck on this question:


Mr Ho used to travel at a speed of 80km/h from town A to town B. He slowed down his speed to 60km/h and reached town B 1 1/2 hours later than usual. Find the distance between town A and Town B.

:?: :?: :?:
Thanks !

[Yu Xuan]

Carrot:

Hi thank you in advance please help me stuck on this question:


Mr Ho used to travel at a speed of 80km/h from town A to town B. He slowed down his speed to 60km/h and reached town B 1 1/2 hours later than usual. Find the distance between town A and Town B.

:?: :?: :?:
Thanks !

Speed Ratio:
Usual : Slower
80 : 60
4 : 3

Time Ratio
Usual : Slower
3 : 4

4u - 3u = 1 1/2h
1 u = 1 1/2h

1 1/2h * 3 = 4 1/2h
4 1 /2h * 80 = 360km

Is 360km that the answer?

[Vanilla Cake]

Carrot:

Mr Ho used to travel at a speed of 80km/h from town A to town B. He slowed down his speed to 60km/h and reached town B 1 1/2 hours later than usual. Find the distance between town A and Town B

Constant distance
Ratio of speed
80 : 60
4 : 3

Ratio of time
3 : 4

Difference in time = 1u = 1½ h = 1.5 h

Distance travelled @ 80 km/h -> 3ux80 = 3x1.5x80 = 360 km
or
Distance travelled @ 60 km/h -> 4ux60 = 4x1.5x60 = 360 km

Distance between town A and Town B was 360 km.

OR

Using algebra and let the distance between town A and Town B be D.
Form an equation to solve:

D/80+3/2=D/60
(D+120)/80=D/60
80D = 60D+7200
20D = 7200
D = 360

Distance between town A and Town B was 360 km.