Q&A - P3 Math

[tianzhu]

deep:

Why is it become 9 and 15? cant understand that..

Hi

The total number of marbles before and after the transfer remains the same. Make the total number of units before and after the same.A common multiple of 3 and 8 is 24.

At first
Benson ----- 3 units ------- 9 units (3*3)
Sharul ------ 5 units ------- 15 units (5*3)
Total ------- 8 units -------- 24 units (8*3)

Do the same for \"In the end\" units.This time multiply each row by 8

In the end.
Benson ----- 2 units -------- 16 units
Sharul ----- 1 unit ------- 8 units
Total ----- 3 units ------- 24 units

Best wishes

[shurley197323]

Pls help. MRS CHENG USED 4/5KG OF 2KG OF SUGAR TO MIX WITH SOME FLOUR. THE AMOUNT OF FLOUR SHE USED IS 1/10KG LESS THAN THE AMOUNT OF SUGAR. WHAT WAS THE MASS OF THE MIXTURE.?

[blessedami]

shurley197323:

Pls help. MRS CHENG USED 4/5KG OF 2KG OF SUGAR TO MIX WITH SOME FLOUR. THE AMOUNT OF FLOUR SHE USED IS 1/10KG LESS THAN THE AMOUNT OF SUGAR. WHAT WAS THE MASS OF THE MIXTURE.?

Hi

Do you mean 4/5 of 2kg of sugar?? :?

If so, then 4/5 of 2kg would be 4/5 of 2000g which is 1600g

Then, since he used 100g (1/10 kg is 100g) less flour, he used 1500g of flour.

So, the total would be 1600g + 1500g = 3100g = 3kg 100g

Not really sure though....

[shurley197323]

Yes.Thanks blessedami. The answer is the same. 3kg100g

[SPI]

I need help on this. Thanks in advance.


3 shirts cost as much as 5 blouse. Mrs Tan bought 2 such shirts and 4 blouses for $110. find the cost of 6 such shirts

[tianzhu]

SPI:

3 shirts cost as much as 5 blouse. Mrs Tan bought 2 such shirts and 4 blouses for $110. find the cost of 6 such shirts

Hi

A common multiple of 3 and 5 is 15.

Shirt ----- 5 units
Blouse ------ 3 units

(2*5) + (4*3) ------ 22 units
22 units ----- 110
1 unit ----- 5

1 shirt ------ $25
6 shirts ----- $150

Best wishes

[meiah]

removed.

[SPI]

:? Why my question 3 shirt became 5 units? Typo error or ? My teacher said can use faction to solve this problem. Can teach me?

tianzhu:

SPI:

3 shirts cost as much as 5 blouse. Mrs Tan bought 2 such shirts and 4 blouses for $110. find the cost of 6 such shirts

Hi

A common multiple of 3 and 5 is 15.

Shirt ----- 5 units
Blouse ------ 3 units

(2*5) + (4*3) ------ 22 units
22 units ----- 110
1 unit ----- 5

1 shirt ------ $25
6 shirts ----- $150

Best wishes

:?

[tianzhu]

SPI:

Why my question 3 shirt became 5 units?

Hi

You may use MD to solve this question.

The bars representing the cost of the 3 shirts and 5 blouses should be of the same size.

Divide first bar into 3 parts to represent 3 shirts,
Divide the second bar into 5 parts to represent 5 blouses.

To compare we need to make the number of units the same. A common multiple 3 and 5 is 15.

Hence shirt ------ 5 units (1/3)
Blouse ------ 3 units (1/5)

Or if you prefer to work using simultaneous concepts, similar to “stars and moons’ type of questions

3S ------ 5B
6S ------ 10B

2S + 4B ------ 110
Multiply by 3 to give
6S + 12B ------ 330

10B + 12B ----- 330
22B ----- 330
1B ------15

10B -----150
Hence, 6S -------150

You may also choose to work by pictorial method instead of alphabet method.

Best wishes

[SPI]

ok thanks Tianzhu.