Q&A - P5 Math

[MathIzzzFun]

chloecube:

hi, need help for the followings:


classes 5A and 5B have the same number of pupils. the ratio of the number of boys in 5A to the number of boys in 5B is 2:3. the ratio of the number of girls in 5A to the number of girls in 5B is 7:4.
a) find the ratio of the number of boys to the number of girls in 5A.
b) if there are 15 fewer girls than boys in 5B, how many pupils are there in 5B?

solution using MD --> http://www.flickr.com/photos/mathizzzfun/5760364658/in/photostream


Since the number of pupils in both classes is the same, the difference of the ratio parts for girls and boys must be the same

boys in 5A : boys in 5B = 2 : 3 --> difference of 1
girls in 5A : girls in 5B 7 : 4 --> difference of 3

make the difference the same :

boys in 5A : boys in 5B --> 6u : 9u ---- difference of 3u
girls in 5A : girls in 5B --- 7u : 4u ----- difference of 3u
Total number of pupils in each class --> 13u

In 5A, ratio of boys : girls = 6 : 7

15 fewer girls than boys in 5B
9u - 4u = 5u
5u --> 15, 1u --> 3

13 x 3 = 39

there are 39 pupils in 5B

cheers.

[MathIzzzFun]

chloecube:

hi, need help for the followings:



container A and container B are identical. container A is 2/3 filled with water while container B is 1/3 filled with water. the ratio of the total mass of container A and its contents to the total mass of container B and its contents is 7:5. the total mass of 2 containers with their contents is 1020g. what is the mass of each empty container?

I think there is a typo error ... 3/3 should be 2/3 ?

one key strategy to use when solving problem sum is --> 'divide and conquer\" .... break up the question into sub-question and find answer to each part first.

I have added a sub-question .. hopefully this help you solve the sum..

container A and container B are identical. container A is 2/3 filled with water while container B is 1/3 filled with water. the ratio of the total mass of container A and its contents to the total mass of container B and its contents is 7:5. the total mass of 2 containers with their contents is 1020g.

a) what is the mass of each container with its contents ?
b) what is the mass of each empty container?

cheers.

[raysusan]

please help me on this qns


grandma had some yellow sweets and some purple sweets in a ratio of 9:7 at first
she make 54 yellow sweets on Mon and gave away 44 purple sweets. she sold 129 yellow sweets on the next day.
the new ratio now is 6:5
how many yellow sweets are there in the end ?

[MathIzzzFun]

raysusan:

please help me on this qns


grandma had some yellow sweets and some purple sweets in a ratio of 9:7 at first
she make 54 yellow sweets on Mon and gave away 44 purple sweets. she sold 129 yellow sweets on the next day.
the new ratio now is 6:5
how many yellow sweets are there in the end ?

using cross multiply --> http://www.flickr.com/photos/mathizzzfun/7069963797/in/set-72157632928079102

using MD/units --> http://www.flickr.com/photos/mathizzzfun/8654441871/in/photostream

cheers.

[chloecube]

MathIzzzFun:

chloecube:

hi, need help for the followings:



container A and container B are identical. container A is 2/3 filled with water while container B is 1/3 filled with water. the ratio of the total mass of container A and its contents to the total mass of container B and its contents is 7:5. the total mass of 2 containers with their contents is 1020g. what is the mass of each empty container?

I think there is a typo error ... 3/3 should be 2/3 ?

one key strategy to use when solving problem sum is --> 'divide and conquer\" .... break up the question into sub-question and find answer to each part first.

I have added a sub-question .. hopefully this help you solve the sum..

container A and container B are identical. container A is 2/3 filled with water while container B is 1/3 filled with water. the ratio of the total mass of container A and its contents to the total mass of container B and its contents is 7:5. the total mass of 2 containers with their contents is 1020g.

a) what is the mass of each container with its contents ?
b) what is the mass of each empty container?

cheers.

So sorry, shld be 3/4.

Hi MathIzzzFun,

can you show me how to do this? thks

[Jamesbond]

To buy a book, Ben started saving $0.40 everyday. Chloe started saving 5 days after Ben started and she saves $0.40 more than Ben everyday. When Ben saved enough money to buy the book, Chloe had already saved $14 more than him. How much does Bens book cost? :frustrated:

[PapayaDad]

After 5 day Ben already save $2 ; Chloe $0


In the end Chloe saved $14 more.

So in total Chloe need to save $16 more.
Since Chloe saved 40 cents more a day, it took Chloe 1600/40 = 40 days.

So Ben saved for 45 days.
The book cost 45 x 40 = $18

[carol73]

hi


pls advise how to draw Model for the below

mrs jeya wants to buy 10 cupcakes, but she is short of $7
if she buys 6 cupcakes, she will have $14 left, how much does each cupcakes cost?

[chloecube]

MathIzzzFun:

chloecube:

hi, need help for the followings:



container A and container B are identical. container A is 2/3 filled with water while container B is 1/3 filled with water. the ratio of the total mass of container A and its contents to the total mass of container B and its contents is 7:5. the total mass of 2 containers with their contents is 1020g. what is the mass of each empty container?

I think there is a typo error ... 3/3 should be 2/3 ?

one key strategy to use when solving problem sum is --> 'divide and conquer\" .... break up the question into sub-question and find answer to each part first.

I have added a sub-question .. hopefully this help you solve the sum..

container A and container B are identical. container A is 2/3 filled with water while container B is 1/3 filled with water. the ratio of the total mass of container A and its contents to the total mass of container B and its contents is 7:5. the total mass of 2 containers with their contents is 1020g.

a) what is the mass of each container with its contents ?
b) what is the mass of each empty container?

cheers.

hi mathizzzfun, i had followed your method of breaking up the question, the answer i got is 289g

[PapayaDad]

carol73:

hi


pls advise how to draw Model for the below

mrs jeya wants to buy 10 cupcakes, but she is short of $7
if she buys 6 cupcakes, she will have $14 left, how much does each cupcakes cost?

hope this help:

<6 cupcake>< $14><$7>

<6 cupcake><4 cupcake>

4 cupcake = 21
1 cup cake = 5.25