Tutor MathsGuru: Ask me for your burning Maths questions!

[MOE Hater]

sachiko:

Thanks MOE Hater.

Welcome

[harish_thiyagrajan.023307hotmail.023307com]

KSP:

tamarind:

Thanks in advance. My friend sent me this question :


I am a three digit number. The digit in the tens place is 6 less than the digit in the hundreds place. The tens place is 2 more than the digit in the ones place. If the digit in the ones place is 5, then I am the number ______.

Is this a P1 question?

Don't be rude, though the question is a bit easy. :celebrate:

[corneyAmber]

tamarind:

Thanks in advance. My friend sent me this question :


I am a three digit number. The digit in the tens place is 6 less than the digit in the hundreds place. The tens place is 2 more than the digit in the ones place. If the digit in the ones place is 5, then I am the number ______.

Is there a typo in the question as in the words in BOLD need to be switched around? :? Otherwise this has to be a 4-digit number.

[corneyAmber]

Au:

KSP:

[quote=\"tamarind\"]Thanks in advance. My friend sent me this question :


I am a three digit number. The digit in the tens place is 6 less than the digit in the hundreds place. The tens place is 2 more than the digit in the ones place. If the digit in the ones place is 5, then I am the number ______.

Is this a P1 question?

Don't be rude, though the question is a bit easy. :celebrate:[/quote]I don't think asking the level of question is rude because this thread has a mixture of level, so it is good for people who try to solve the questions to know what level is the question.

[CoffeeCat]

tiger262:

Can anyone kindly put up a solution for this question:


Cars are travelling to and fro from Greens Town to Sins City. The cars leave the Towns at regular interval and a car will meet another car coming in the opposite direction at every 6 min. Ronald starts cycling from Greens Town to Sins City while Annie starts cycling in the opposite direction. Both leave the Towns at the same time. Ronald and Annie will meet a car coming in the opposite direction every 7 and 8 min respectively. They met each other after cycling for 56 min. What is the time taken by a car to travel from Greens City to Sins City?

Thank you very much.

may I ask what's the source of this question? This looks very very simlar to the last question of smops 2009.

[tiger262]

CoffeeCat:

tiger262:

Can anyone kindly put up a solution for this question:


Cars are travelling to and fro from Greens Town to Sins City. The cars leave the Towns at regular interval and a car will meet another car coming in the opposite direction at every 6 min. Ronald starts cycling from Greens Town to Sins City while Annie starts cycling in the opposite direction. Both leave the Towns at the same time. Ronald and Annie will meet a car coming in the opposite direction every 7 and 8 min respectively. They met each other after cycling for 56 min. What is the time taken by a car to travel from Greens City to Sins City?

Thank you very much.

may I ask what's the source of this question? This looks very very simlar to the last question of smops 2009.

This question was asked by my friend's son who is a P6 student. I am sorry that I am unable to locate the source.

I was very impressed with this thread. So many kind people are helping with their time and effort to solve difficult problems. I am sure someone can post a solution with explanations so that a P6 student can understand. Kindly help out. Thanks a lot.

[Vanilla Cake]

tiger262:

Cars are travelling to and fro from Greens Town to Sins City. The cars leave the Towns at regular interval and a car will meet another car coming in the opposite direction at every 6 min. Ronald starts cycling from Greens Town to Sins City while Annie starts cycling in the opposite direction. Both leave the Towns at the same time. Ronald and Annie will meet a car coming in the opposite direction every 7 and 8 min respectively. They met each other after cycling for 56 min. What is the time taken by a car to travel from Greens City to Sins City?

tiger262:

This question was asked by my friend's son who is a P6 student. I am sorry that I am unable to locate the source.
I was very impressed with this thread. So many kind people are helping with their time and effort to solve difficult problems. I am sure someone can post a solution with explanations so that a P6 student can understand. Kindly help out. Thanks a lot.

Hi tiger262,
While waiting for someone to post a solution with explanations so that a P6 student can understand, pls refer to solutions from Uncle Observer:

http://psle2010a.blogspot.com/2010/06/speed-p6_22.html dated Tue, 22 June 2010
http://prischoolmaths.blogspot.com/2009/11/speed_30.html dated Mon, 30 Nov 2009.

Dear readers:Take note that this question was already available sometime late last year (2009).

[CoffeeCat]

Uncle Observer is amazing for already posted solutions to many questions asked in this forum and vanilla is amazing for locating them.


For such challenging speed questions it will definitely aids in understanding if you draw the usual distance line thingy.
First I define the car’s speed to be x km/min. Notice that all the cars are a certain distance from each other.
First, from "a car will meet another car coming in the opposite direction at every 6 min", the distance between each car will be 12x km.
From "Ronald and Annie will meet a car coming in the opposite direction every 7 and 8 min respectively.", let’s look at ronald.
Imagine at the 7th min, it has just met a car. now it is going to met the next car in 7 mins. In that 7 mins the car would have covered 7x km. Ronald will have to cover 5x km in 7 mins.
Similarly Annie will have to cover 4x km in 8 mins.

In order to answer the question we need to find the distance in terms of x.
So in 56 mins, Ronald will have covered 85x = 40x km,
and Annie will have covered 74x = 28x km.
Total distance 68x km.
Time taken = 68mins.

[Almighty]

Thank you dharma

[tiger262]

Thank you so much Vanilla Cake for locating the solutions. Your speed in locating them is amazing.


But honestly the solutions could be understood only with the lucid explanations offered by Coffeecat. Thanks to you Coffeecat. Without you, I would still be trying to make sense of Uncle’s solutions.

Coffeecat and Vanilla cake are both phenomenal in their contributions.