Q&A - PSLE Math

[AJH]

Thank you. Another question:


David and Michael drove from Town A to Town B at different speeds.
Both of them kept their speeds constant throughout their journey.
David started his journey 30 mins earlier than Michael.
However, Michael reached Town B 50 mins earlier than David.
When reached Town B, David had travelled 4/5 of his journey and was 75 km away from Town B.

a.What is the distance between Town A and Town B?
b. How far could David travel in an hr?
c. What was the time taken by Michael to travel from Town A to Town B?

[2cor41618]

AJH:

Thank you. Another question:


David and Michael drove from Town A to Town B at different speeds.
Both of them kept their speeds constant throughout their journey.
David started his journey 30 mins earlier than Michael.
However, Michael reached Town B 50 mins earlier than David.
When reached Town B, David had travelled 4/5 of his journey and was 75 km away from Town B.

a.What is the distance between Town A and Town B?
b. How far could David travel in an hr?
c. What was the time taken by Michael to travel from Town A to Town B?

(a)
David had travelled 4/5 of his journey and was 75 km away from Town B.

The above implies that 1/5 of the distance between Town A and B is 75 km, thus
dist. btw Town A and B= 75 x 5 = 375 km

(b)Michael reached Town B 50 mins earlier than David.

This means that David took 50 mins to travel 75 km, therefore
5/6 hr--> 75 km
1 hr--> 75 x 6/5 =90 km

(c) David started his journey 30 mins earlier than Michael.
However, Michael reached Town B 50 mins earlier than David.

This means that Michael took 80 mins or 1 1/3 hr less than David to reach Town B.

We can work out the time taken for David to reach Town B first:
375/90 = 4 1/6 hrs

So, Michael took 4 1/6 - 1 1/3 = 2 5/6 hrs

[tamunawara]

Hi Please help me with these two problems


1. The ratio of the number of male workers to the number of female workers in a factory is 7:3. 1/9th of the female workers are skilled workers. 1/7 th of the male workers are skilled. there is total of 168 skilled workers in the factory. How many male workers are there in the factory.

2. Susan, Alice and Lynn had a total of $378. Alice gave susan $54 and as a result, Alice had $90 more than Lynn. the final ratio of the sum of Alice’s money to Susan’s money was 4:5. How much did susan have at first.

[MathIzzzFun]

tamunawara:

Hi Please help me with these two problems


1. The ratio of the number of male workers to the number of female workers in a factory is 7:3. 1/9th of the female workers are skilled workers. 1/7 th of the male workers are skilled. there is total of 168 skilled workers in the factory. How many male workers are there in the factory.

2. Susan, Alice and Lynn had a total of $378. Alice gave susan $54 and as a result, Alice had $90 more than Lynn. the final ratio of the sum of Alice's money to Susan's money was 4:5. How much did susan have at first.

Hi

Q1.
Ratio of male : female = 7 : 3 --> 21u : 9u
1/9 of female are skilled workers --> 1u
1/7 of male are skilled workers --> 3u
Total 4u --> 168, 1u --> 42... can you complete the solution from here.

Q2.
In the end, Alice : Susan --> 4u : 5u
Lynn --> 4u -90
Total --> 13u - 90 = 378, 1u --> 36 ... can you complete the solution from here?

cheers.

[Maths Hub]

Change the ratio from 7:3 to 21:9 so that male multiple of 7 and female multiple of 9

Therefore there are 1 unit of skill female and 3 units of skill male
4 units = 168
21 units = 884 male workers

[tamunawara]

thanks a lot

[Spongy]

Hi its me again asking 3 questions this time thank you very much!


1. Alan’s monthly income is $250 more than Clare but their monthly expenditure are the same. Over a certain period of time, Alan has saved $1350 but Clare saved only $600. Given that each of them spends $500 a month, how long does Clare take to save $600?

2. Alan and Ben were given some money each. If Alan spent $45 each week and Ben spent $90 each week, Alan would still have $840 left when Ben spent all his money. If Alan spent $90 each week and Ben spent $45 each week, Alan would still have $210 left when Ben had spent all his money. How much money did Alan receive?

3.Mrs Lim spend $834 on some pants and shirts. The amount of money spent on the pants was $66 more than the amount of money spent on the shirts. She bought 3/4 times as many pants as shirts. Each shirt cost $9 lesser than each pants. What was the total number of pants and shirts bought by Mrs Lim?

[tianzhu]

Spongy:

2. Alan and Ben were given some money each. If Alan spent $45 each week and Ben spent $90 each week, Alan would still have $840 left when Ben spent all his money. If Alan spent $90 each week and Ben spent $45 each week, Alan would still have $210 left when Ben had spent all his money. How much money did Alan receive?

Hi

Please refer to this similar type of question.

You may apply the same strategy to your question.

The answer to your question is $1050.

Best wishes

http://farm6.static.flickr.com/5142/5614468685_555807d62e_z.jpg\">

[tianzhu]

Spongy:

1. Alan's monthly income is $250 more than Clare but their monthly expenditure are the same. Over a certain period of time, Alan has saved $1350 but Clare saved only $600. Given that each of them spends $500 a month, how long does Clare take to save $600?

Hi

1350 – 600 ------ 750

750/250 ------ 3

Clare takes 3 months to save $600.

Best wishes

[2cor41618]

Spongy:

3.Mrs Lim spend $834 on some pants and shirts. The amount of money spent on the pants was $66 more than the amount of money spent on the shirts. She bought 3/4 times as many pants as shirts. Each shirt cost $9 lesser than each pants. What was the total number of pants and shirts bought by Mrs Lim?

Amt spent on pants-->($66 + $834)/2 =$450
Amt spent on shirts-->$450 - $66 = $384

Pants: Shirts= 3u : 4u

3u of pants cost $450
1u of pants cost $150

4u of shirts cost $384
1u of shirts cost $96

Diff btw 1u of pants and 1u of shirts--> $150 - $96 = $54
Diff btw 1 pants and 1 shirt --> $9

Thus, 1u--> $54/$9 = 6

Total number of pants and shirts--> 6 x 7 = 42

Ans: 42