Q&A - P4 Math

[jieheng]

milo-cupcake:

Hi, can anyone help with the following question?


There were 308 adults and children in a concert. After 5/6 of the adults and 1/4 of the children left the concert, there were an equal number of adults and children left. How many adults were there at first?

Thanks in advance.

A [----][----][----][----][----][----]
C [][][][]

A [][][][][][][][][][][][][][][][][][] --> 18u
C [][][][] --> 4u

18u + 4u --> 308
22u --> 308
1u --> 14

18u --> 18*14 = 252

No. of adults were there at first = 252

[MathIzzzFun]

fohope:

Jenny had 3/7 as much money as Kenny. If they spent $252 each, Jenny's money will be only 2/7 of Kenny's. How much money did Kenny have more than Jenny

http://i46.tinypic.com/eizye.png\">



Hi,
Can anyone solve this by using model or other method?
After reading the answer, I still dont understand.
Thanks in advance.

For the posted solution, I have applied the ratio method using fractions. Key concept here is : \"difference remains the same\" since same amount of money was spent.

So, make the difference in the ratio parts or in this case the numerator & denominator the same.

This question can also be solved by applying the equal fraction method -
http://www.tinyurl.com/mathizzzfun-equalfractions

solution at http://www.flickr.com/photos/mathizzzfun/8612801525/in/photostream

cheers.

[Poppet]

During a quiz, a correct answer would be awarded 3 points while 2 points would be deducted for a wrong answer.For every 6 questions attempted, Kathy managed to get 5 of them correct.Given that Kathy scored a total of 104 points, how many questions did Kathy answer correctly?


Can anyone help to solve this problem sum?

:thankyou: :?:

[MathIzzzFun]

Poppet:

During a quiz, a correct answer would be awarded 3 points while 2 points would be deducted for a wrong answer.For every 6 questions attempted, Kathy managed to get 5 of them correct.Given that Kathy scored a total of 104 points, how many questions did Kathy answer correctly?


Can anyone help to solve this problem sum?

:thankyou: :?:

Score for each set of 6 questions (5 correct, 1 wrong)
= 5 x 3 - 2 = 13

104/13 = 8 sets --> 8 x 5 = 40

Kathy answers 40 questions correctly.

cheers.

[fohope]

Hi,

Pls help me with this question. Thank you in advance.

The total cost of 2 books and 3 pens is SGD43.
Each book costs S$4 more than the total cost of the 3 pens.
What is the cost of the book and pen?

[tianzhu]

fohope:

Hi,

Pls help me with this question. Thank you in advance.

The total cost of 2 books and 3 pens is SGD43.
Each book costs S$4 more than the total cost of the 3 pens.
What is the cost of the book and pen?

Hi

Please confirm.

Each book costs S$4 more than the total cost of the 3 pens or the cost of 1 pen?

Best wishes

[fohope]

Hi Tianzhu,


The question is correct.

Thanks.

[tianzhu]

Hi fohope


Basing on the original question, you still can get an answer, but it’ll not be in nice whole numbers.

(3P+4) + ((3P+4) + 3P ---- 43

The answers will be in decimals.

Best wishes

[arthurt]

Hi,


Need help on this question.

Mr Imran paid a total of $120 for 6 plates and 8 cups. If each plate costs twice as much as a cup, find the cost of a dozen plates.

Thanks

[tianzhu]

arthurt:

Hi,


Need help on this question.

Mr Imran paid a total of $120 for 6 plates and 8 cups. If each plate costs twice as much as a cup, find the cost of a dozen plates.

Thanks

Hi

There are a few options.You may use MD,letters of the Alphabet or Units.

Alphabet Method

Each plate costs twice as much as a cup.

P ----2C

Mr Imran paid a total of $120 for 6 plates and 8 cups.

12C + 8C ------ 120

20C ------ 120

C ------ 6

Cost per plate ------ 12

Cost of a dozen plates ------144

Units Method

C ----- 1u

P ---- 2u

20u ------ 120

1u ------- 6

2u -------12

Cost per plate ------ 12

Cost of a dozen plates ------144

Best wishes