Speed Question

Harry and Martin cycled from Town X to Town Y at constants speed.
Harry took 4 hours to cycle the whole journey.
Martin took 2.5 hours to cycle 3/4 of the whole journey.
Find the ratio of Harry's speed to Martin's speed.

Solution

Pei Chun Public Sch 2007 PSLE Math Prelim Q43

Taufik arranged a rectangle and a square and painted them in three colours as shown in the figure below.


THe ratio of the area of the rectangle to that of the square is 3:1.
The ratio of the area of the red part to that of the blue part is 4:1.
The length of the square is 9 cm.
a) What is the area of the purple part?
b) What is the ratio of the area of the purple part to that of the figure?

Solution

Speed Question

Uncle Tom is going to deliver some good from his shop to a customer in a town.
If he travels at an average speed of 30km/h , he will reach the town at 1pm.
If he travels at a speed of 40km/h, he will reach the town at 11am.
What should his average speed be if he wants to reach the town at 12 noon?

Solution



if travelling at 40km/h, he will be 60km faster.
In 1hr, he is 10km/h faster

60/10 = 6
6 x40= 240
Therefore you took 6hrs to travel 240km

240/7 =34.28
The average speed should be 34.28km/h to reached the town at 12.00pm

2007 PSLE Math Question

2007 PSLE Math Question

There are some workers. They arranged chairs into short rows and long rows.
There are 18 short rows and 7 long rows.
Each long row has 16 more chairs than the short row.
Half of the chairs are arranged into long rows while
3/7 of chairs are arranged in short rows.
The rest of the remaining chairs are stacked in a corner.

a) What fraction of the chairs are stacked in the corner?
b) How many chairs are arranged in rows?


Solution

There are 7 units of chair altogether
(draw 7 units )

Nanyang Primary School 2007 PSLE Math Prelim

Henry Park Pri Sch 2007 Prelim Q48