Q&A - P4 Math

[tracywham]

Hi, I need help to solve these 2 problems:


a) A tank is 1/3 full. After 12 litres of water were added, it was 5/6 full.
What was the capacity of the tank?

b) A basket 1/2 full of longans has a mass of 8 kg. The same basket full of
longans has a mass of 11 kg. What is the mass of the empty basket?

[PiggyLalala]

5/6 -1/3 = 5/6-2/6 =3/6 =1/2

Therefore 1/2 the capacity of jar = 12 litres
Capacity of jar = 12×2=24 litres

B) 1/2 longan = 11-8 = 3 kg
Empty Basket:8 -3 =5kg

[tracywham]

Thanks for your quick reply… can i ask answer for (a)… capacity of tank where does the "2" (12 x 2) comes from?


and also for (b) why do i use 8-3? thank you

[PiggyLalala]

tracywham:

Thanks for your quick reply... can i ask answer for (a).. capacity of tank where does the \"2\" (12 x 2) comes from?


and also for (b) why do i use 8-3? thank you

Capacity of 1/2 the jar = 12 litres
capacity of a jar ( 1 whole = 1/2 jar + 1/2 jar ) = 12 x 2 litres = 24 litres

b) Mass of 1/2 longan + empty basket = 8 kg
mass of basket + mass of one basket full of longan = 11 kg
therefore mass of 1/2 longon = 11 - 8 = 3 kg
and mass of empty basket = 8 - 3 = 5 kg.

[yorky_plume.016347yahoo.016347com.016347sg]

Dear all,


I need your assistance :?: for the below question as I have encounter difficuties. Thanks

Mary used 6 pieces of $2 notes to exchange for 20 cents coins and 50 cents coins. He had 3 more 50 cents coins than 20 cents coins from the exchange. Find the total number of coins he received from the exchange.

:thankyou:
AT

[yorky_plume.016347yahoo.016347com.016347sg]

quekcc:

AT:

Dear all,


I need your assistance :?: for the below question as I have encounter difficuties. Thanks

Mary used 6 pieces of $2 notes to exchange for 20 cents coins and 50 cents coins. He had 3 more 50 cents coins than 20 cents coins from the exchange. Find the total number of coins he received from the exchange.

:thankyou:
AT

Grouping 1 x 20 cents and 1 x 50 cents = 1 x 70 cents
Since Mary got 3 more 50 cents, we will deduct $1.50 from $12, which is $10.50.

Divide 1050 cents by 70 cents and we got 15 x 70 cents.

So the number of coins = 15 x 2 + 3 = 33

OMG..i interpret that from the exchange, there are 3 more 50 cents coins for every 20 cents coin exchanged.
Thanks quekcc.
:thankyou:

[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.

[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.

[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.