Q&A - P3 Math

[qms]

Daddy:

Bobby places 12 c


ards on a table. Each card is either red or black in colour. If the fraction of black cards is 7/12, what is the smallest number of additional cards that Bobby needs to put on the table so that the function of black cards becomes 5/8?

There are 12 cards, out of which 7 are black.

10/16, in its simplest form, is equivalent to 5/8.

Hence, Bobby needs to put at least another 4 cards on the table, hoping to get 3 black cards and 1 red card so that the function of black cards becomes 5/8, since he currently has 7 black cards out of the 12 cards.

Correct? http://i827.photobucket.com/albums/zz200/pepper2010_bucket/ththbnbnb.gif\">

[BigDevil]

Not sure if I understand the question correctly.


Currently, black cards are 7/12 = 14/24

Target 5/8 = 15/24.

So smallest number of additional cards to be placed = 1

[qms]

BigDevil:

Not sure if I understand the question correctly.


Currently, black cards are 7/12 = 14/24

Target 5/8 = 15/24.

So smallest number of additional cards to be placed = 1

BigD, if you pick one more card, there will be a total of 13 cards. So, even if you pick a black card, the function of black card becomes 8/13.

The number of cards to be picked must be such that we should be able to eventually achieve 5/8 of black card.

Right? http://i114.photobucket.com/albums/n264/pcreasy/questionmarkbiggersmiley.gif\">

[plum-cake]

BigDevil:

Not sure if I understand the question correctly.


Currently, black cards are 7/12 = 14/24

Target 5/8 = 15/24.

So smallest number of additional cards to be placed = 1

12 to 24 means 12 more cards not 1 right?
:?

[qms]

plum-cake:

12 to 24 means 12 more cards not 1 right?

:?

What BigD meant was that the question asked for function of black cards to be 5/8. If you consider multiples of 8 and 12, the common denominator is 24. Hence, converting 7/12 gives 14/24, while converting 5/8 gives 15/24.

Since the target is 5/8, which is the same as 15/24, you just need to place one more card to make it 15/24.

However, my point is, placing one more card will mean the final fraction is either 7/13 or 8/13. It won't give you 5/8, regardless of the multiples you consider.

[plum-cake]

qms:

plum-cake:

12 to 24 means 12 more cards not 1 right?

:?

What BigD meant was that the question asked for function of black cards to be 5/8. If you consider multiples of 8 and 12, the common denominator is 24. Hence, converting 7/12 gives 14/24, while converting 5/8 gives 15/24.

Since the target is 5/8, which is the same as 15/24, you just need to place one more card to make it 15/24.

However, my point is, placing one more card will mean the final fraction is either 7/13 or 8/13. It won't give you 5/8, regardless of the multiples you consider.

Thanks qms,
got it.

[BigDevil]

I see what you mean, qms.

But that sounded too cheem for P3, no??

[qms]

BigDevil:

I see what you mean, qms.

But that sounded too cheem for P3, no??

http://i74.photobucket.com/albums/i255/tele5/smiley/signqtb9.gif\">

Actually, the question itself is very cheem, too. It's rather vague and subject to many interpretations. Best if the member who raised this question (Daddy) clarifies.

[Daddy]

Hi all,


Thanks for the anwser.
The correct anwser is 4 cards.

[HAPPYH]

Draw a shape with 4 sides and 2 smaller angles.


Does it mean the shape drawn should have 4 sides and only 2 smaller angles? oe can it be 4 sides with at least 2 smaller angles (can be more than 2 smaller angles)?

Please help me to understand this question. Thank you.