The figure is not drawn to scale. What fraction of the figure is the total area of the shaded regions A, B, C, D, E, F, G and H?

Solution

The base of the whole figure is (4 + 3 + 6 + 3 + 2) cm = 18 cm

1st row from the top

Fig A has a base of 6 cm.

2nd row

The sum of the bases of Figs B and C is 6 cm.

3rd row

The sum of the bases of Figs D and E is 6 cm.

4th row

The sum of the bases of Figs F and G is 6 cm.

5th row

Fig H has a base of 6 cm.

The average length of the bases of all shaded figures is 6 cm.

The length of the base of the whole figure is 18 cm.

Therefore, the fraction of whole figure that is shaded is

6 cm divided by 18 cm = 1/3

Answer: 1/3

Note that the above method can be used because the vertical columns also correspond to the 6 cm shaded out of the 18 cm total vertical length of the figure.

This blog is managed by Song Hock Chye, author of Improve Your Thinking Skills in Maths (P1-P3 series), which is published and distributed by EPH.

## Friday, September 25, 2009

### Rosyth Sch 2007 PSLE Math Prelim Q44

Labels:
Four Sided Figures,
Mathematics

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## 3 comments:

Emm...i still don't understand this question.can you please explain a bit furthur?

yea abit confusing . ><

so damning easy!!! I wish PSLE would be harder than this!!!

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