Q&A - PSLE Math

[tianzhu]

Shimmer:

Does anyone knows how to solve these two question ?

:thankyou:
Q1 At 9.30am, a car left town X for town Y at a speed of 60km/h for the whole journey. At 11am a lorry started from town Y and travelled towards town X. The speed of the lorry remained the same until it passed the car at 12.30pm. The lorry passed the car at midpoint between town X and town Y and decreased its speed by 20km/h, it travelled at new speed for the rest of the journey. What time did the lorry reach town X ?

Hi

For questions on Speed, it’s useful to start with a simple diagram.

9.30am ----- 12.30pm ----- 3h

Car travelled 3*60 ------ 180km

11am ----- 12.30pm ------ 1.5h

Speed of lorry ------ 180/1.5 ------ 120km/h

Lorry’s new speed ------ 100km/h

180/100 ----- 1.8h ------ 1h 48

Hence, the lorry reached Town [email protected]

Best wishes

[Shimmer]

Thanks Tianzhu, you are surperb !!

[tianzhu]

Shimmer:

Q2 Container A and B are containers with the same square base. Conainer A contains water filled to the brim while container B is empty. After 288cm cubic of water is poured into Container B from Container A, the depth of water in Container B is 60% the depth of water left in container A. What is the length of the square base of Container B ? (Sorry not able to attached the diagram but its show that Container A the height is 48cm)

Hi

I am trying to understand the question without the diagram.

Just to check if I am on the right track is the answer 4 cm?

Best wishes

[Shimmer]

tianzhu:

Shimmer:

Q2 Container A and B are containers with the same square base. Conainer A contains water filled to the brim while container B is empty. After 288cm cubic of water is poured into Container B from Container A, the depth of water in Container B is 60% the depth of water left in container A. What is the length of the square base of Container B ? (Sorry not able to attached the diagram but its show that Container A the height is 48cm)

Hi

I am trying to understand the question without the diagram.

Just to check if I am on the right track is the answer 4 cm?

Best wishes

Dear Tianzhu

I do not have the answer and unable to upload the diagram.

Thanks

[tianzhu]

Shimmer:

Dear Tianzhu

I do not have the answer and unable to upload the diagram.

Thanks

Hi

Where is this question from?

Ok, I'll make an attempt to draw the diagram.I'll assume that Container B's height is less than that of Container A.(Whether more or less does not affect the answer)

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8281/7512509418_6a135b071e_z.jpg\">

[Shimmer]

tianzhu:

Shimmer:

Dear Tianzhu

I do not have the answer and unable to upload the diagram.

Thanks

Hi

Where is this question from?

Ok, I'll make an attempt to draw the diagram.I'll assume that Container B's height is less than that of Container A.(Whether more or less does not affect the answer)

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8281/7512509418_6a135b071e_z.jpg\">

Dear Tianzhu

This question was from my daughter's tution teacher. Yes, the diagram shows container B is higher than A.

Thanks

[mumworks]

Hi


Anyone can help with this Math question ?

The distance between Town X and Town Y was 303 km. Martin left Town X at 5pm, travelling at 96 km/h. Diana left Town X 15 mins earlier, driving at 36 km/h slower than Martin.
(a) At what time did Martin overtake Diana ?
(b) When Martin reached Town Y, how far away from Town X was Diana ?

Thanks in advance.

[tianzhu]

mumworks:

Hi


Anyone can help with this Math question ?

The distance between Town X and Town Y was 303 km. Martin left Town X at 5pm, travelling at 96 km/h. Diana left Town X 15 mins earlier, driving at 36 km/h slower than Martin.
(a) At what time did Martin overtake Diana ?
(b) When Martin reached Town Y, how far away from Town X was Diana ?

Thanks in advance.

Hi

This is a question On “catch up”.

It’s useful to start with a simple diagram.

Diana left Town X 15 mins earlier.

In 15 mins, she covered 15/60*60 which is 15 km.

15/36 ----- 5/12 (25mins)

Martin overtook [email protected] pm.

Martin met Diana at 25/60*96 which is 40km.

For (b) there are different approaches to do it.

303 – 40 ----- 263

Time taken by martin to travel 263 km ------ 263/96 h

Distance travelled by Diana at the same duration ------- 263/96*60 -------- 164.375

Diana was (164.375 + 40) from Town X which is 204.375km

Best wishes

[whitety]

Hi, need help to solve this qn.


A train left a terminal with some passengers. At station A, 3/5 of these passengers alighted and 50 passengers boarded the train. At station B, 118 passengers alighted and 38 passengers boarded the train. The number of passengers on the train now is 1/3 the number of passengers on the train when it left the terminal.
a) Find the number of passengers on the train when it left station B
b) How many passengers were there on the train when it left the terminal?

Thanks!

[Michaelia0816]

Thx, I understood , Tianzhu!