Tutor MathsGuru: Ask me for your burning Maths questions!

[Tang]

Dharma:

Daddy:

Hi,


Another ratio problem to solve :? Please help. Thanks

1. 2/5 of P is equal to 3/10 of Q. 1/2 of R is equal to Q. Express P as a simple ratio to R

Thanks

2/5 P = 3/10 Q
P/Q = 3/10 x 5/2 = 3/4
P : Q = 3 : 4

Q = 1/2 R
Q/R = 1/2
Q : R = 1 : 2 = 4 : 8
so, P : R = 3 : 8

Hi,

2/5 x 3/3 = 6/15

3/10 x 2/2 = 6/20

1/2 x 20/20 = 20/40

15 :40 = 3 :8

[pineapple tarts]

Good day Maths Guru,


I am stucked with this one.

A group of children paid a total of $364 for a trip. Each girl paid $10 and each boy paid a dollar less. If there were 6 girls more than boys, how many boys were there in the group?

Other than using the guessing method (draw the table), is there other solution?

Many thanks

[autolycus]

pineapple tarts:

Good day Maths Guru,


I am stucked with this one.

A group of children paid a total of $364 for a trip. Each girl paid $10 and each boy paid a dollar less. If there were 6 girls more than boys, how many boys were there in the group?

Other than using the guessing method (draw the table), is there other solution?

Many thanks

The price is roughly $10 per person.

So there must be 37 children at least, maybe 38.

Since there are 6 girls more than boys, it must be an even number (boys = girls, plus another 6 girls). Right, so total = 38.

Take out those 6 extra girls, boys + girls (same number of each) = 32.

So there must be 16 boys + 16 girls + 6 extra girls.

Now let's check.

16 x $9 = $144
22 x $10 = $220

Total = $364. Yay!

[pineapple tarts]

autolycus:

The price is roughly $10 per person.

So there must be 37 children at least, maybe 38.

Since there are 6 girls more than boys, it must be an even number (boys = girls, plus another 6 girls). Right, so total = 38.

Take out those 6 extra girls, boys + girls (same number of each) = 32.

So there must be 16 boys + 16 girls + 6 extra girls.

Now let's check.

16 x $9 = $144
22 x $10 = $220

Total = $364. Yay!

Many thanks Autolycus !!

So I have to ask my P4 DD to guess guess with this type of question?

[autolycus]

pineapple tarts:

Many thanks Autolycus !!


So I have to ask my P4 DD to guess guess with this type of question?

Not really...

Think of it this way. If they were all girls at $10, it would be too easy. But let's think about boys as girls with $1 discount ($9 instead of $10).

Then we are trying to find out how many people got a discount.

We know the total number = boys + girls = boys + (boys + 6).

So it is an even total number and it must be more than 36 (paid more than $360, right?). The next highest even number is 38.

If nobody got a discount, that's 38 x $10 = $380.

But the discount is $380-$364 = $16.

So we got total discount of $16, there must be 16 boys (each with $1 discount).

When we check, 16 boys + (16+6) girls, that also gives the same answer!

[autolycus]

I guess the point we can make is that for such problems, we can try many methods. It depends on what your DD’s preferred way of thinking really is.


Hope that helps!

[kancheongmum]

pineapple tarts:

Good day Maths Guru,


I am stucked with this one.

A group of children paid a total of $364 for a trip. Each girl paid $10 and each boy paid a dollar less. If there were 6 girls more than boys, how many boys were there in the group?

Other than using the guessing method (draw the table), is there other solution?

Many thanks

Hi pineapple tarts

I have another method that use reasoning, alternative way of looking at this type of question.

Given that there were 6 more girls, we take away the amount paid by the 6 girls from the total $364

$364 - $60 = $304

So $304 is the amount paid by the equal no. of girls and boys.

1 group --- 1 boy and 1 girl --- $10 + $9 = $19

No. of group ---- $304/$19 ----- 16

So there are 16 boys and 22 girls

Hope this helps

[pineapple tarts]

OMG !! Many thanks to Autolycus and Kancheongmum !! You guys are of great help !! :salute: Now even myself got a clearer pics & I can explain to my DD confidently tonite. :oops: heee...


Personally, I do not like guess guess. even guess guess must also have a basis or some reasons. That's why I am stucked at $304 for so long. Once again. thank you very very much!!

[Koi_BubbleTea]

Hi Maths Guru,


Pls help & Thanks In Advance.
- WRITE A NUMBER SENTENCE WITH A TOTAL OF 7,USING SUBTRACTION.

[wkong]

Hi All,


Need help in the following:-

madam mariam bought some minced chicken. she packed the meat equally into packets of 1/5kg each. If she packed the meat equally into packets of 1/7kg each, she will get 10 more packets of minced chicken. how many kilograms of minced chicken did she buy?

Thanks,
wkong