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primary 5 | Maths | Rate & Ratio
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Macdaddy
Macdaddy

primary 5 chevron_right Maths chevron_right Rate & Ratio chevron_right Singapore

Help me please

Date Posted: 4 years ago
Views: 341
Eric Nicholas K
Eric Nicholas K
4 years ago
The question seems faulty. Based on the diagram, if A:B is 7:3, then E:C must also be 7:3. It cannot be 8:2.
Eric Nicholas K
Eric Nicholas K
4 years ago
Having said that, the question is still solveablt. Note that triangle D has the same base and height as rectangles A and B combined. So, the area of triangle D must be half of the sum of rectangles A and B.

Since the areas of the left half and the right halt are the same, each half must occupy 162 cm2 of area. So, rectangles A and B occupy a total of 162 cm2 (while the three triangles occupy a total of 162 cm2).

This means that D occupies an area of 81 cm2.

Now, A and B exist in the ratio 7:3.

10 units = 162 cm2
1 unit = 16.2 cm2
7 units = 113.4 cm2

So the area of rectangle A is 113.4 cm2.

Total area of rectangle A and triangle D
= 113.4 + 81
= 194.4 cm2

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Macdaddy
Macdaddy's answer
14 answers (A Helpful Person)
1st
I might not be correct
Eric Nicholas K
Eric Nicholas K
4 years ago
B is not exactly the “square”. The entire shape is the square of 324 cm2.

So, 3 units is not equal to 324 cm2 as you wrote in the first line.

Presentation wise, there is clearly room for improvement because without stating what the numbers represent, the values are just a bunch of multiplications and additions without much meaning.