Q&A - P5 Math

[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.

[esibuyer]

Hi, can help to solve the following question for my girl.

Grandma is 80 years old and his son is 52 years old. How many years ago was Grandma thrice as old as his son?
Thanks

[MathIzzzFun]

esibuyer:

Hi, can help to solve the following question for my girl.

Grandma is 80 years old and his son is 52 years old. How many years ago was Grandma thrice as old as his son?
Thanks

Hi

Age difference will always remain the same.

Age difference = 80 - 52 = 28
When grandma was 3 times as old as her son,
grandma's age --> 3u
son's age --> 1u
age difference --> 2u
2u --> 28, 1u --> 14
52-14 = 38 years ago

cheers.

[MathIzzzFun]

yxl:

Q1)Kenny bought two bags of rice, X and Y. The two bags contained diferent

amounts of rice which had a total mass of 90kg. Kenny poured 1/4 of the
rice from Bag X into Bag Y. After that, he poured 2/5 of the rice from
Bag Y into Bag x. He found that both bags had the same mass now.
How much rice was ther in Bag y at the beginning?


Q2) Marcus earns $350 less than Terry every month. They each spend $800
every month and save the rest of their money.

a) How long does it take for marcus to save $2100 and for Terry to save
$4550.

b) What is Marcus's monthly salary?

Hi

Q1.

In the end,
mass of rice in Bag X = mass of rice in Bag Y = 45kg

Before 2/5 of rice transferred from Y to X,
Mass of rice in Y = 45 / 3 x 5 = 75 kg
Mass of rice in X = 90 kg - 75 kg = 15 kg

At first,
Mass of rice in Y = 75 kg - 15/3 = 70 kg

Q2.

Terry will save $ 350 more than Marcus every month
$4550 - $2100 = $2450
$ 2450 / $ 350 = 7

It will take 7 months for Terry to save $4550 & Marcus to save $ 2100.

Marcus savings/month = $ 2100/7 = $ 300
Marcus salary = $ 300 + $ 800 = $ 1100

cheers.

[MathIzzzFun]

nhps2012:

Hi MathIzzzFun


Thank you so much for your help.

Cheers.

u r welcome

cheers.

[thmejlfm]

Thank you. :thankyou:

[esibuyer]

Many thks

MathIzzzFun:

yxl:

Q1)Kenny bought two bags of rice, X and Y. The two bags contained diferent
amounts of rice which had a total mass of 90kg. Kenny poured 1/4 of the
rice from Bag X into Bag Y. After that, he poured 2/5 of the rice from
Bag Y into Bag x. He found that both bags had the same mass now.
How much rice was ther in Bag y at the beginning?


Q2) Marcus earns $350 less than Terry every month. They each spend $800
every month and save the rest of their money.

a) How long does it take for marcus to save $2100 and for Terry to save
$4550.

b) What is Marcus's monthly salary?

Hi

Q1.

In the end,
mass of rice in Bag X = mass of rice in Bag Y = 45kg

Before 2/5 of rice transferred from Y to X,
Mass of rice in Y = 45 / 3 x 5 = 75 kg
Mass of rice in X = 90 kg - 75 kg = 15 kg

At first,
Mass of rice in Y = 75 kg - 15/3 = 70 kg

Q2.

Terry will save $ 350 more than Marcus every month
$4550 - $2100 = $2450
$ 2450 / $ 350 = 7

It will take 7 months for Terry to save $4550 & Marcus to save $ 2100.

Marcus savings/month = $ 2100/7 = $ 300
Marcus salary = $ 300 + $ 800 = $ 1100

cheers.

[kyy]

Appreciate if someone can help with this question. Thanks!


The school bus can carry 24 adults or 40 children. If there are already 15 adults and 13 children on the bus, how many more children can the bus carry?