Welcome to Test-paper.info
Saturday, February 24 2018 @ 03:24 PM CST
 Select a Forum » General Chat » Primary 1 Matters » Primary 2 Matters » Primary 3 Matters » Primary 4 Matters » Primary 5 Matters » Primary 6 Matters » Question, Feedback and Comments » Education Classified
 Forum Index >  Test Paper Related >  Primary 6 Matters P6 Math RSS 2012 SA1
 | Printable Version
 By: acelow (offline)  Saturday, September 21 2013 @ 08:27 AM CDT (Read 578 times)
acelow

The distance between Town A and Town B was 350km. A car left Town A for Town B at 1pm with an average speed of 70km/h. A lorry left Town B for Town A at 12 noon with average speed of 50km/h . Assuming that both car and lorry travelled at a constant speed throughout the journey, at what time would the car and the lorry be 20km apart after the 2 vehicles pass each other?

Pls help again
Thank You

Newbie

Registered: 05/02/09
Posts: 14

 By: echeewh (offline)  Saturday, September 21 2013 @ 08:02 PM CDT
echeewh

Hey <acelow>,

Appreciate that you put in the <Answerkey> as well , whenever possible.

Following is my worked solution:

d(AB ) = 350 km
sC = 70 km/h
sL = 50 km/h

At 1pm (13 00) the lorry (L) would have travelled 50km. Thus distance separating car (C) and L is 300 km.

In order for C and L to be 20 km apart after passing each other, distance separating them is 320 km. Thus ...

time taken = 320 ÷ (70 + 50)
= 320 ÷ 120
= 2 2/3 hrs
= 2 hrs 40 mins

time = 13 00 + 2 40 = 15 40 = 3.40pm

==========

Trust this helps.

Do let me know again if this is different from your <Answerkey> or if there's further clarification.

Cheers,
Edward

Active Member

Registered: 04/21/11
Posts: 627

 All times are CST. The time is now 03:24 pm.
 Normal Topic Locked Topic Sticky Topic
 New Post Sticky Topic w/ New Post Locked Topic w/ New Post
 View Anonymous Posts Able to Post HTML Allowed Censored Content