Q&A - PSLE Math

[tianzhu]

isetan:

Hi,


Got a speed problem here. Need some help as below:-

Car P left Town A for Town B at the same time when Car Q left Town B for Town A. The average speed of Car P was 56 km/ hr and the average speed for Car Q was 72km/hr. the two cars passed each other at a point 24km from the midway of the two towns. What is the distance between Town A and Town B? Ans given is 384km.

Hi

When two cars are travelling in opposite directions, the sum of individual distances in equal to the total distance between them.

There are a few approaches to this question.

It helps to start with a simple diagram.

One possible way.

In 1h, P and Q covered 128 km (56+72).

In 1h, they passed each other at 8 km from the midpoint, 64km (128/2)

8km ----- 1h

24km ------- 3h

Therefore in 3h, they are 24km from the midpoint.

Distance between A and B ------- 3*128 ------ 384 km.

Best wishes

[isetan]

tianzhu:

isetan:

Hi,


Got a speed problem here. Need some help as below:-

Car P left Town A for Town B at the same time when Car Q left Town B for Town A. The average speed of Car P was 56 km/ hr and the average speed for Car Q was 72km/hr. the two cars passed each other at a point 24km from the midway of the two towns. What is the distance between Town A and Town B? Ans given is 384km.

Hi

When two cars are travelling in opposite directions, the sum of individual distances in equal to the total distance between them.

There are a few approaches to this question.

It helps to start with a simple diagram.

One possible way.

In 1h, P and Q covered 128 km (56+72).

In 1h, they passed each other at 8 km from the midpoint, 64km (128/2)

8km ----- 1h

24km ------- 3h

Therefore in 3h, they are 24km from the midpoint.

Distance between A and B ------- 3*128 ------ 384 km.

Best wishes

Thanks Tian Zhu.

[zanen]

MathIzzzFun:

zanen:

hello can someone help me wif my hw? Justin baked some pies. 1/3 of the pies were chicken pies & the rest were vegetable pies. He packed 3/4 of the vegetable pies into big boxes & the rest of the vegetable pies into small boxes. each big box of vegetable pies made up 1/12 of the total no. of pies. Each small box of vegetable pies made up 1/16 of the total no of pies.


How many big boxes of vegetable pies were there?

How many small boxes of vegetable pies were there?

pls check text highlighted in blue - should it be \"He packed 3/4 of the vegetable pies into small boxes & the rest of the vegetable pies into big boxes\"

or \"Each small box of vegetable pies made up 1/16 of the total no of pies\" should be \"Each small box of vegetable pies made up 1/18 of the total no of pies.\"

cheers.

sorry typo shld be \"He packed 3/4 of the vegetable pies into small boxes & the rest of the vegetable pies into big boxes\"
please help TIA

[MathIzzzFun]

zanen:

hello can someone help me wif my hw? Justin baked some pies. 1/3 of the pies were chicken pies & the rest were vegetable pies. He packed 3/4 of the vegetable pies into small boxes & the rest of the vegetable pies into big boxes. Each big box of vegetable pies made up 1/12 of the total no. of pies. Each small box of vegetable pies made up 1/16 of the total no of pies.


How many big boxes of vegetable pies were there?

How many small boxes of vegetable pies were there?

chicken pies : vegetable pies = 1:2 --> 2u : 4u -- total number of pies --> 6u
number of vegetable pies in small boxes : big boxes
--> 3u : 1u ---- total 4u

number of vegetable pies in small boxes as a fraction of total number of pies = 3/6 = 1/2 = 8/16
8/16 = 8 x 1/16 ---> 8 small boxes of vegetable pies

number of vegetable pies in big boxes as a fraction of total number of pies = 1/6 = 2/12
2/12 = 2 x 1/12 ---> 2 big boxes of vegetable pies

cheers.

[GLORYmum]

wrong posting

[susutoo]

hi,

please help


Thank you!

[susutoo]

hi,

sorry forget to attached image
http://i45.tinypic.com/nqusdd.jpg\">

[peggy]

Kindly assist with this speed.


A car travelled from Town X to Town Y. After traveling for 1 3/4h, the car passed a van traveling at an average speed of 55 km/h in the opposite direction. When the car reached Town Y 3 h later, the van was 35km away from town x.
A. Find the ave speed of the car.
B. Find the distance between town x n town y.

Thanks.

[tianzhu]

Hi moderators


Please help to delete.

Best wishes

[tianzhu]

peggy:

Kindly assist with this speed.


A car travelled from Town X to Town Y. After traveling for 1 3/4h, the car passed a van traveling at an average speed of 55 km/h in the opposite direction. When the car reached Town Y 3 h later, the van was 35km away from town x.
A. Find the ave speed of the car.
B. Find the distance between town x n town y.

Thanks.

Hi

You may wish to take a look at this similar question.

Hope this helps.

Best wishes

http://farm9.staticflickr.com/8301/7947589604_f3d0dc949b_z.jpg\">