Q&A - P3 Math

[christina soh]

small:

You are welcome, ttyh....

Please help. Thank you.

1. Jo has $146 and her sister, Mary has $338. Each of them bought a present to their mother on her birthday of the same price. Now, the money left with Mary is 4 times of Jo. What is the price of the present ?

2. Ali has twice the amount of money than Bob. Bob has thrice the amount of money than Jim. If Ali has $40 more than Jim, how much money does Ali has ?

[tianzhu]

Hi


Hope this helps.

Best wishes.

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[tianzhu]

christina soh:

2. Ali has twice the amount of money than Bob. Bob has thrice the amount of money than Jim. If Ali has $40 more than Jim, how much money does Ali has ?

Hi

For your second question, due to time constraints, I’ll give some pointers for you to draw the MD.

Jim --- 1 unit
Bob ----- 3 units
Ali ----- 6 units

6 -1 ------- 5
5 units ------- 40
1 unit -------8

Ali ------- 6 units -------48

Best wishes

[rocklee]

Dear all Maths Experts out there,


Below are two P4 questions extracted from one of the 2010 Top scchool exam papers:

Q1. At a party, every girl was given 4 bars of chocolate and every boy was given 5 bars of chocolate. There were 5 times as many boys as girls at the party. Given that a total of 232 bars of chocolate were given out, how many boys were at the party?

Q2. Tin A contains some 20-cents coins and Tin B contains some 50-cents coins. There are 9 more coins in Tin A than Tin B. The amount of money in Tin A is $2.70 less than that in Tin B. How many 50-cents coins are there in Tin B?

As kids are not exposed to algebra at P4, I have solved the above problem sums using "Guess and Check" method. Does anyone have an alternative solution to share?

Thanks,

[atutor2001]

rocklee:

Q1. At a party, every girl was given 4 bars of chocolate and every boy was given 5 bars of chocolate. There were 5 times as many boys as girls at the party. Given that a total of 232 bars of chocolate were given out, how many boys were at the party?

Q2. Tin A contains some 20-cents coins and Tin B contains some 50-cents coins. There are 9 more coins in Tin A than Tin B. The amount of money in Tin A is $2.70 less than that in Tin B. How many 50-cents coins are there in Tin B?

Q1 Method - work in groups

Break the pupils into groups of 5 boys and 1 girl.
Each group would need = 5x5 (boys) + 1x4 (girls) = 29 bars

232 / 29 = 8 groups
8 x 5 = 40 boys

Q2 Method - make their numbers equal

Add 9 more 50c coins to B so that no. of coins is same as A
Additional money added to B = 9x 50 c = $4.50

With 9 more 50c coins in B, A will be less than B by = $2.70+$4.50 = $7.20

That is when both Tins have same number of coins, the Total difference = $7.20

Difference between 1 pair (i.e. one 50c and one 20c) = 50-20 = 30c

No. of pairs of coins = Total difference / Difference of 1 pair = 720/30 = 24 pairs

24-9=15 fifty cent coins (minus 9 to remove the 9 coins we have added in for easy calculation)

Both methods very clumsy - algebra gooood

[rocklee]

Hi atutor2001, thanks alot.

[christina soh]

tianzhu:

christina soh:

2. Ali has twice the amount of money than Bob. Bob has thrice the amount of money than Jim. If Ali has $40 more than Jim, how much money does Ali has ?

Hi

For your second question, due to time constraints, I’ll give some pointers for you to draw the MD.

Jim --- 1 unit
Bob ----- 3 units
Ali ----- 6 units

6 -1 ------- 5
5 units ------- 40
1 unit -------8

Ali ------- 6 units -------48

Best wishes

Thank you Tianzhu. Another question:-

There are 200 egss in Basket X and Basket Y. If you transfer 20 eggs in Basket X to Basket Y, there are still 14 more eggs in Basket X than Basket Y. How many eggs in Bakset X at first?

[tianzhu]

christina soh:

Thank you Tianzhu. Another question:-

There are 200 egss in Basket X and Basket Y. If you transfer 20 eggs in Basket X to Basket Y, there are still 14 more eggs in Basket X than Basket Y. How many eggs in Bakset X at first?

Hi

You're welcome.

Due to time constraints, I’ll give you some pointers without drawing the MD.

In the end, there are still 14 more eggs in Basket X than Basket Y.

Basket X ------- 107 eggs
Basket Y ------- 93

At first

Basket X ------107 + 20 --------127.

Best wishes

[Muffins]

christina soh:

Thank you Tianzhu. Another question:-


There are 200 egss in Basket X and Basket Y. If you transfer 20 eggs in Basket X to Basket Y, there are still 14 more eggs in Basket X than Basket Y. How many eggs in Bakset X at first?

If you transfer internally, the total will still remain as 200, so:

200 - 14 = 186

186 ÷ 2 = 93 → Y after the transfer

200 - 93 = 107

107 + 20 = 127

Hope this helped

[small]

MD..


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