Q&A - PSLE Math

[tianzhu]

WenLee:

i couldn't solve this question after many attempts. :?


Jerry, Kathy and Luqman had a total savings of $450.60. The ratio of Kathy’s savings to Luqman’s savings was 3 : 5 at first. After Jerry and Kathy each gave 1/3 of their money to charity, the 3 children had $363.90 left. How much savings did Jerry have at first?

Hi WenLee

SA2 is around the corner and you may need the solution urgently.

A quick one,please draw a MD based on the description.Hope I've made no calculation errors.

Draw 1 bigger block to represent 1 unit for Jerry(1J) and 1 smaller block(1u) for Kathy and Luqman.

At first
3J ---Jerry
3u ----- Kathy
5u ----- Luqman

In the end
2J ------ Jerry
2u ------ Jerry
5u ------- Luqman

3J+3u+5u ------ 450.6 -----First
2J+2u+5u ------- 363.90 -----End

1J+1u ------ 86.70
3J+3u ------ 260.10
5u ------ 190.50
1u ------38.10

Therefore Jerry ----- 145.80

Best wishes

[WenLee]

[quote]\"At first

3J ---Jerry
9u ----- Kathy
15u ----- Luqman

In the end
2J ------ Jerry
6u ------ Jerry
15u ------- Luqman\"[/quote]Hi tianzhu

I am puzzled how u managed to get 9u and 15u for Kathy and Luqman? Can the working be started directly using 1J + 1U = $86.70, and work out Luqman's savings?

[yeodo]

Hi Parents


Can you please help with this question :

Luke spent 45% of his monthly income. For the month of July, his income was 30% less than August. His expenses for July was $648 less than his expenses for August. What was his income in August?

[tianzhu]

WenLee:

I am puzzled how u managed to get 9u and 15u for Kathy and Luqman? Can the working be started directly using 1J + 1U = $86.70, and work out Luqman's savings?

Hi

When I first read the question, I mistakenly read Lugman as giving 1/3 away. That's why I changed the 5 units into 15 units to allow for the 1/3 portion. In giving the solution I forgot to change the equivalent ratio back to 3:5.

Yes, you can use 1J+1U -----86.70 as Kathy is giving 1/3 away. You should get the same answer.

I am sorry for the inconvenience.Please refer to revised solution.

Best wishes

[WenLee]

[quote]Hi


When I first read the question, I mistakenly read Lugman as giving 1/3 away. That why I changed the 5 units into 15 units to allow for the 1/3 portion. In giving the solution I forgot to change the equivalent ratio back to 3:5.

Yes, you can use 1J+1U -----86.70 as Kathy is giving 1/3 away. You should get the same answer.

I am sorry for the inconvenience.Please refer to revised solution.

Best wishes[/quote]Hi tianzhu

Thank you v much for your help. Appreciated it very much.

[tianzhu]

WenLee:

Thank you v much for your help. Appreciated it very much.

Hi

You're welcome.

Best wishes

[yeodo]

Hi Parents


Please help with this question :

Luke spent 45% of his monthly income. For the month of July, his income was 30% less than August. His expenses for July was $648 less than his expenses for August. What was his income in August?

[TLK]

ANSWER =$6,240.00

[tianzhu]

yeodo:

Hi Parents


Please help with this question :

Luke spent 45% of his monthly income. For the month of July, his income was 30% less than August. His expenses for July was $648 less than his expenses for August. What was his income in August?

Hi

A quick one, as you may need the solution while preparing for SA2.

We are comparing with the income in August.The income for August is our base (100%).

When income for July decreases by 30%, there is a corresponding decrease in Luke’s spending.

30/100*45% ----- 13.5%
13.5% of his income in August was $648.
Therefore 100% of his income ----- 4800.

Hope this helps.

Best wishes

Check

August
Income ----- 4800
Spending ----- 2160

July
Income ----- 3360
Spending ------ 1512

Therefore difference ------(2160-1512) ------648

[tianzhu]

leesf:

Can you enlighten me on the above? Sorry, I still can't see the pattern from the above. Thanks

Hi leesf

Good Morning,please refer to Dharma's solution which was posted earlier in this thread.

Best wishes