Tutor MathsGuru: Ask me for your burning Maths questions!

[kwcllf]

The ratio of Ahmad’s age to Suri’s is 5:3 now. 4 years ago, the ratio was 7:4. How old is Ahmad now?

[kwcllf]

The ratio of Ahmad’s age to Suri’s is 5:3 now. 4 years ago, the ratio was 7:4. How old is Ahmad now?

[MathIzzzFun]

kwcllf:

The ratio of Ahmad's age to Suri's is 5:3 now. 4 years ago, the ratio was 7:4. How old is Ahmad now?

Hi

For problem sums on \"age\", the key is the age difference will remain the same.

Ratio of Ahmad's age to Suri's age, four years ago = 7:4 (difference of 3) = 14u : 8u (difference of 6u)
Ratio of Ahmad's age to Suri's age, now = 5:3 (difference of 2) = 15u : 9u (difference of 6u)

So, 15u - 14u = 1u = 4
Ahmad's age now = 15 x 4 = 60 years old.

cheers.

[kwcllf]

Thanks Again MathIzzzFun!

[MathIzzzFun]

kwcllf:

Thanks Again MathIzzzFun!

u r welcome

cheers.

[rrjan]

Could all the kind maths gurus kindly help me with this question? Its a P3 question. Sincere thanks


Mrs Lim buys 3 kg of beef and has $15 left. If she wants to buy 4 kg of beef, she would need $3 more. How much money does Mrs Lim have?

[MathIzzzFun]

rrjan:

Could all the kind maths gurus kindly help me with this question? Its a P3 question. Sincere thanks


Mrs Lim buys 3 kg of beef and has $15 left. If she wants to buy 4 kg of beef, she would need $3 more. How much money does Mrs Lim have?

Hi

reply posted at the P3 thread.

cheers.

[starry15]

Hi where is p3 thread? I’ve another question taken from p3 Onsponge. I’ve difficulty explaining to my gal. Hope to get some enlightenment here.


Miss Lim bought a packet of sweets to distribute to her class. If each child gets 3 sweets, she would be left with 30 sweets. If each child gets 5 sweets, she would need 5 more sweets.
A) how many children are there in her class?
B) how many sweets did Miss Lim have at first?

[MathIzzzFun]

starry15:

Hi where is p3 thread? I've another question taken from p3 Onsponge. I've difficulty explaining to my gal. Hope to get some enlightenment here.


Miss Lim bought a packet of sweets to distribute to her class. If each child gets 3 sweets, she would be left with 30 sweets. If each child gets 5 sweets, she would need 5 more sweets.
A) how many children are there in her class?
B) how many sweets did Miss Lim have at first?

Hi

You can post the P3 questions at this forum - http://www.kiasuparents.com/kiasu/forum/viewforum.php?f=66

Could you check the question - something is amiss...

The \"normal\" way to solve this type of question is to list out the multiples eg. 3,6,9,12 etc and then add 30 to the multiples, do the same for multiples of 5 and subtract 5 (there might be error in the question, it should be an even number - 30 + 5 = 35), and then find the total which tally for both for same number of children.


The question can also be looked from this perspective;
- I have 30 sweets to give to some children, if I were to give 2 sweets to each child, I would need 6 more. How many children were there ?

Total number of sweets needed = 30 + 6 = 36, number of children = 36/2 = 18

For the posted question.. we can assume that each child had 3 sweets, so for each child to get 5 sweets, each will get 2 more sweets - so it becomes similar to the above eg. except that the total number of sweets differ.

cheers.

[starry15]

MathizzFun,

My mistake. It should be :

Miss Lim bought a packet of sweets to distribute to her class. If each child gets 3 sweets, she would be left with 30 sweets. If each child gets 4 sweets, she would need 5 more sweets.
A) how many children are there in her class?
B) how many sweets did Miss Lim have at first?

The answer is 35 kids. Onsponge solution is that by adding 1 sweet per child = 30+5 sweets (short fall plus extra). Hence the answer is 35 kids. Using multiples may be very time consuming in this example so Onsponge solution is quick and accurate. But my problem is how to explaib to my gal. She gave me a blank look when I tried to explain :?: