Tutor MathsGuru: Ask me for your burning Maths questions!

[SKT]

Thank you Dharma.

[Herbie]

I have one qn.


15. A bullet train took 5 hours to travel from Patient Town to Honest Town while an electric train took 4 hours longer to travel from Honest Town to Patient Town. Both trains set off at the same time and moved towards each other. Two hours later, they were 255 km apart. What was the speed of the electric train?

CHIJ St Nicholas 2009

[corneyAmber]

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[corneyAmber]

http://i724.photobucket.com/albums/ww246/ks2me/P6Mathmoneyterry.jpg\">

[Muffins]

Herbie:

I have one qn.


15. A bullet train took 5 hours to travel from Patient Town to Honest Town while an electric train took 4 hours longer to travel from Honest Town to Patient Town. Both trains set off at the same time and moved towards each other. Two hours later, they were 255 km apart. What was the speed of the electric train?

CHIJ St Nicholas 2009

Hi Herbie, this is how I do it.

You have to remember that if you want to know the ratio of their speeds, you will have to REVERSE the hour timings, so:

In 1 hour
BT ==> 9 units
ET ==> 5 units.

So, in 2 hours

BT==> 18 units
ET ==> 10 units

Since the electric train takes (5 + 4 = 9) hours to go the full distance, and 10 units are 2 hours, 7 hours (9-2 hours) would be: (10 X 7)/2 = 35 units

35 units = 18 units + 255km (remaining distance)

So, 255 km = 17 units.

1 unit = 255/17 = 15km

15km X 5 = 75km (What the electric train can go to in 1 hour)

75km/1h = 75km/h

Hope I helped!

[Almighty]

Ngserene617:

Hi kindly assist me for the below 3 stated questions, thanks.


3. 3 sisters, Amy, Bonnie and Cindy shared to buy a present for their mother. Amy paid 1/3 of the amount which Bonnie and Cindy paid. Bonnie paid 1/5 of the amount which Amy and Cindy paid. If Cindy paid $30 more than Bonnie, how much did the present cost?


Thanks kindly help me to solve this !

A:B+C:T =1:3:4------ 3:9:12
B:A+C:T= 1:5:6 -------2:10:12
A:B:C= 3:2:[9-2]
5 units--- $30
12 units---?[$72]
Is the answer $72/-?

[Vanilla Cake]

Ngserene617:

3. 3 sisters, Amy, Bonnie and Cindy shared to buy a present for their mother. Amy paid 1/3 of the amount which Bonnie and Cindy paid. Bonnie paid 1/5 of the amount which Amy and Cindy paid. If Cindy paid $30 more than Bonnie, how much did the present cost?

Concept - Total unchanged

A : B+C
1 : 3
3 : 9

B : A+C
1 : 5
2 : 10

A: 3u
B: 2u
7u

C-D=(7-2)u= 5u
5u=$30
Total cost of present = (3+2+7)u= 12u= $30/5x12= $72

Ngserene617:

Thanks kindly help me to solve this !

Pls kindly state the level (P6 or P5) of your questions and source.

[Ngserene617]

mathsguru:

Original Title: Let MathsGuru Answer Your Burning Maths Questions!


:welcome:

Dear Parents,

Are you frustrated/stuck when helping your child solve his/her Maths questions? Are you inclined to use Algebra most of the time? Do you have difficulty trying to use diagrams or other heuristic methods (that Primary School students learn) to solve?

:idea: Post your questions here and see how MathsGuru solve them to the best of her ability. Detailed solutions will be posted back in this thread.

Hi mathguru can u help me for this question 3;
3. 3 sisters, Amy, Bonnie and Cindy shared to buy a present for their mother. Amy paid 1/3 of the amount which Bonnie and Cindy paid. Bonnie paid 1/5 of the amount which Amy and Cindy paid. If Cindy paid $30 more than Bonnie, how much did the present cost?

Thanks



So start asking and watch this space!!

Cheers :celebrate: ,
MathsGuru

P/S (Disclaimer, in case you're wondering...):
Although MathsGuru is a full-time Maths tutor, this thread is meant to be an absolutely free resource for parents (or even children) with no strings attached. Just someone who's passionate about Maths and wanna spread the fun in learning Maths with others.

[corneyAmber]

Ngserene617, have you looked at Almighty’s and VanillaCake’s solution?

Is the answer $72?

[firebird]

Dear maths guru


Good evening.

Please help me on the following P6 maths:

1) There are 2/5 as many girls as boys in a class. What fraction of the pupils in the class are boys?

2) Mr. Chong and Mr. Tan had $87. Mr. Tan and Mr. Ng had $115. If the amount of money Mr.Chong had was 3/7 of the amount Mr. Ng had, how much did Mr. Tan have?

3) At a party, there were some ballons. 25 balloons burst and 10% of the remaining balloons flew away. If only 60% of the balloons were left, how many balloons were there at first.

4) Packets A, B and C each contained some cement. 1/3 of the cement was transferred from Packet A to Packet B. Then 1/3 of the cement was transferred from Packet B to Packet C. Finally 1/3 of the cement was transferred from Packet C to Packet A. In the end there were 12 kg of cement in each packet. What was the mass of cement in Packet B at first?

5)A club had 150 members last year, This year, the number of male members reduced by 20%. As a result, there are now as many male members as female members. How many members does the club has this year?

6) A car and a lorry which were 80km apart started to travel towards each other at the same time. The car was 40Km/h faster than the lorry. They went past each other after 2/5 hours.
a) How far did the lorry travel when it passed the car?
b) Find the speed of the lorry.

Many thanks
firebird