Q&A - P5 Math

[nhps2012]

Can somebody help me:


Jewel bought some pens and wanted to put them into boxes. If she put 4 pens into each box, there would be 3 pens left. If she put 6 pens into each box, she would have 5 pens left.

If the number of pens was between 100 and 150, how many pens did Jewel buy?

Thank you!

[MathIzzzFun]

nhps2012:

Can somebody help me:


Jewel bought some pens and wanted to put them into boxes. If she put 4 pens into each box, there would be 3 pens left. If she put 6 pens into each box, she would have 5 pens left.

If the number of pens was between 100 and 150, how many pens did Jewel buy?

Thank you!

hi

find number = multiple of 12 minus 1 in the range of 100-150.
4 possible answers - 107, 119, 131, 143

cheers.

[nhps2012]

MathIzzzFun:

nhps2012:

Can somebody help me:


Jewel bought some pens and wanted to put them into boxes. If she put 4 pens into each box, there would be 3 pens left. If she put 6 pens into each box, she would have 5 pens left.

If the number of pens was between 100 and 150, how many pens did Jewel buy?

Thank you!

hi

find number = multiple of 12 minus 1 in the range of 100-150.
3 possible answers - 119, 131, 143

cheers.

Hi MathIzzzFun

Thank you very much for your help.

Your answer is the same as mine. 4 possible answers 107, 119, 131, 143.

The problem I had is how do I present the solution.

Once again, thank you very much for your help.

[MathIzzzFun]

nhps2012:

MathIzzzFun:

[quote=\"nhps2012\"]Can somebody help me:


Jewel bought some pens and wanted to put them into boxes. If she put 4 pens into each box, there would be 3 pens left. If she put 6 pens into each box, she would have 5 pens left.

If the number of pens was between 100 and 150, how many pens did Jewel buy?

Thank you!

Hi MathIzzzFun

Thank you very much for your help.

Your answer is the same as mine. 4 possible answers 107, 119, 131, 143.

The problem I had is how do I present the solution.

Once again, thank you very much for your help.

[/quote]hi

Oops..morning blues..computed for range 110-150.
For such questions, the usual method is to list which will be tedious for this question.
Looking at the remainder, we have:
Divide by 4--> remainder 3
Divide by 6 --> remainder 5
So, adding 1 to the number will make it divisible by 4 & 6, so find multiples of 4 & 6 in the given range and subtract 1 to get the number.


cheers.

[nhps2012]

Hi MathIzzzFun


Thank you so much for your help.

Cheers.

[thmejlfm]

Jack and Jill had some red seeds each.

If Jack were to give Jill 41 of his seeds, both of them would have the same number of seeds.
If Jill were to give Jack 41 of her seeds, Jack would have twice as many seeds as Jill.
How many seeds did each of them have?

Thank you

[thmejlfm]

Q.: Three tins, A, B and C, contained a total of 240 cookies.

Some cookies from A were transferred to B and the number of cookies in B was doubled.
Then some cookies from B were transferred to C and the number of cookies in C was doubled.
As a result of this, there was an equal number of cookies in each tin.
How many cookies were in each time at first?

Thank you :?:

[PiggyLalala]

thmejlfm:

Q.: Three tins, A, B and C, contained a total of 240 cookies.

Some cookies from A were transferred to B and the number of cookies in B was doubled.
Then some cookies from B were transferred to C and the number of cookies in C was doubled.
As a result of this, there was an equal number of cookies in each tin.
How many cookies were in each time at first?

Thank you :?:

After: each tin has equal cookies, that is, 240/3 = 80 each.
Then work backward: before: cookies in tin 80/2 = 40
before giving to C some cookies: cookies in B : 80 + 40 = 120
before recieving some cookies from A: cookies in B = 120/2 = 60.
therefore originally A has 60 + 80 = 140 cookies, B: 60 and 40

[thmejlfm]

Thank you.


Can help me at the other question under topic Need Help?

Thank you very much

[PiggyLalala]

thmejlfm:

Jack and Jill had some red seeds each.

If Jack were to give Jill 41 of his seeds, both of them would have the same number of seeds.
If Jill were to give Jack 41 of her seeds, Jack would have twice as many seeds as Jill.
How many seeds did each of them have?

Thank you

let Jack : m seeds and Jill: n seeds
therefore m - 41 = n + 41
m = n + 82 --------- (1)

similarly, m + 41 = 2(n-41)
m + 41 = 2n - 82
m = 2n -123
from (1) n + 82 = 2n - 123
82 + 123 = n
n = 205.
m = 205 + 82 = 287
Jack = 287: Jill = 205

I think this question can be solve easily using model too. But i prefer to solve it by simple simultaneous equations. If your child can handle simple simultaneous equations( with no fraction ), it will be great as she can then use it to solve almost all sums involving fractions, ratios and percentages and there is no need to remember all the various heuristic methods.