Tutor MathsGuru: Ask me for your burning Maths questions!

[MMM]

MMM:

I've a question :


The cost of 2 soccer balls and 3 basketballs is $190. The cost of 3 soccer balls and 4 basketballs is $265. What is the cost of 1 basketball and 1 soccer ball respectively?

Hi,

I managed to solve it. Wondering if there are better ways.

2 soccer balls 3 basketballs $190
3 soccer balls 4 basketballs $265
1 soccer balls 1 basketballs $75 ($265 - $190)
2 soccer balls 2 basketballs $150 ($75 * 2)
1 basket ball $40 ($190-$150)
1 soccer ball $35 ($75-$40)

[sachiko]

Thank you Sister

sister:

This is the \"After\" situation:

Tank ---> 12 units
Pail -----> 1 unit

Since the total volume of water remain constant,

13 units = 8346 ml
1 unit = 8346 / 13 = 642 ml

Pail = 1 unit = 642 ml

Ans. At first, Pail = 642 + 314 = 956 ml

[YLH88]

[quote]Jim bought some chocolates and gave half of it to Ken. Ken bought some sweets and gave half of it to Jim.Jim ate 12 sweets and Ken ate 18 chocolates.The ratio of Jim's sweets to chocolates became 1 : 7 and the ratio of Ken's sweets to chocolates Ken became 1:4.How many sweets did Ken buy? [/quote]
Hi Mathsguru,

A very happy Chinese New Year !!

So sorry to trouble you straight after the CNY holiday :oops: but I can't get the solution for the below question. This question is very similar to the above Jim and Ken question. I tried using the same method but still not able to get the answer. Therefore, I have no choice but to trouble you again.

Question
Jack had some watermelons. He gave half of his watermelons to Terry. Terry then gave half of his durians to Jack. Jack sold 212 watermelons and Terry sold 56 durians. In the end, the ratio of watermelons to durians for Jack and Terry is 1:8 and 1:2 respectively. How many watermelons did Jack have at first?

Below is my half baked solution, not sure which part I gone wrong :?

Thank you very much!

Wishing all parents in this forum a very happy Chinese New Year !!
http://www.postimage.org/image.php?v=Pqkpy29

[tianzhu]

Hi YLH88


Happy New Year.

I am no mathsguru, hope the solution from an amauterish dad helps.

http://farm5.static.flickr.com/4064/4363880677_0e30e3bb8a_o.jpg\">

[BigDevil]

tianzhu:

Hi YLH88


Happy New Year.

I am no mathsguru, hope the solution from an amauterish dad helps.

http://farm5.static.flickr.com/4065/4364553434_78668a9edc_o.jpg\">

Hi tianzhu,

The question asked how many watermelons Jack had at first, ie before he gave half to Terry. So shouldn't the anwer be (292 x 2) = 584?

[tianzhu]

BigDevil:

The question asked how many watermelons Jack had at first, ie before he gave half to Terry. So shouldn't the anwer be (292 x 2) = 584?

Hi BigDevil

You are correct.The answer is 584.

I apologise for my silly error.I've revised my solution.

Best wishes

[BigDevil]

tianzhu:

BigDevil:

The question asked how many watermelons Jack had at first, ie before he gave half to Terry. So shouldn't the anwer be (292 x 2) = 584?

Hi BigDevil

You are correct.The answer is 584.

I apologise for my silly error.

Best wishes

No, no...no apologies necessary. I'm sure it's just an oversight.
In fact, must thank you for the solution. I was cracking my head, trying to solve it without resorting to algebra! :lol:

[tianzhu]

Hi YLH88


If you prefer to do it by tabulated form, here is the alternative.For this question, I'd suggest MD.

http://farm3.static.flickr.com/2706/4364057007_f2862089a8_o.jpg\">

Best wishes

[YLH88]

Hi Tianzhu & BigDevil,


Thank you very much! Trying to digest the solution.

But I still don't understand, when I compare the solution with the Jim and Ken question, the initial unit and part did not include the number that was eaten for the Jim and Ken question but here it is included. When do I have to include and when do I not include ??
:?


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

[tianzhu]

YLH88:

But I still don't understand, when I compare the solution with the Jim and Ken question, the initial unit and part did not include the number that was eaten for the Jim and Ken question but here it is included. When do I have to include and when do I not include ??
[/url]

Q1) Jim bought some chocolates and gave half of it to Ken. Ken bought some sweets and gave half of it to Jim. Jim ate 12 sweets and Ken ate 18 chocolates. The ratio of Jim's sweets to chocolates became 1 : 7 and the ratio of Ken's sweets to chocolates Ken became 1:4.How many sweets did Ken buy?

Q2) Jack had some watermelons. He gave half of his watermelons to Terry. Terry then gave half of his durians to Jack. Jack sold 212 watermelons and Terry sold 56 durians. In the end, the ratio of watermelons to durians for Jack and Terry is 1:8 and 1:2 respectively. How many watermelons did Jack have at first?

Hi

Put these two questions side by side and compare the differences.
Look pretty much similar, but take note of the subtle differences.

In the first question, Jim ate the sweets given by Ken. For the second question, Jack sold his remaining half of his water melon.

Best wishes