Q&A - PSLE Math

[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!

[tianzhu]

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!

Hi

You may use MD or work using units.

At point of leaving terminal ------ 15 units

At point of leaving Station A ----- 6 units + 50

At station B

118 – 38 ------ 80

6 units + 50 – 80 ------- 6 units – 30

This is 1/3 the number of passengers on the train when it left the terminal.

6 units – 30 ----- 5 units

Hence, 1 unit ----- 30
\t
Number of passengers on the train when it left station B ------ 6*30 – 30 ------ 150

Number of passengers on the train when it left the terminal ------- 15*30 ------ 450

Best wishes

[Michaelia0816]

Help with this question,


A car, travelling a constant speed, took 9 hours to travel from Town Y to Town Z. A lorry, travelling at a constant speed, took 18 hours to travel from Town Z to Town Y. Both vehicles started at the same time and they met when there were 180km from Town Z.
(a) Find the distance between the two towns.
(b) Find the speed of the car.

[tianzhu]

Michaelia0816:

Help with this question,


A car, travelling a constant speed, took 9 hours to travel from Town Y to Town Z. A lorry, travelling at a constant speed, took 18 hours to travel from Town Z to Town Y. Both vehicles started at the same time and they met when there were 180km from Town Z.
(a) Find the distance between the two towns.
(b) Find the speed of the car.

Hi

I am not too sure if inverse proportion way of solving speed questions is taught to all students in schools.

You may use it if you are familiar with it.

It's helpful to start with a simple diagram.

Time ratio

Car: Lorry ------ 9:18 ----- 1:2

Shorter time means faster speed.

With faster speed, greater distance is covered.

Distance covered by car ------ 2 units

Distance covered by lorry ------ 1 unit

1 unit ------ 180

Distance between towns ------ 3 units ------ 540 km

Speed of car------ 540/9 ------ 60 km/h

Best wishes

[Michaelia0816]

Thx Tianzhu

[Michaelia0816]

Pls try not to use algebra, I am easily confused. Help with this Qn,


Motorist takes 1/2 h less than the usual time to travel from Town K to Town J when he increases his average speed by 10%. For a distance of 100km, he will take 1/3 h less than the usual time if his speed is 20% more than the average speed from Town K to Town J. Find the distance between Town K and Town J.