Hi Jessica,

Following pls find my worked solutions:

*** - for alignment purpose

Q9

Given that Shaded Area : Unshaded Area is 1 : 8,

Area of DEFG (whole figure) = 9u

Area of triangle DGF = (9/2)u

Shaded Area : Area of triangle DGF

***** 1 ****** : **** (9/2)

Multiply this ratio 2x, we have ...

***** 2 ****** : ***** 9

Ans: **2 : 9**

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Q20

Shaded Area : Area of A

**** 8 ******* : *** 13 ***** -- (1)

Shaded Area : Area of B

**** 4 ******* : *** 5 ******* -- (2)

Given that Shaded Area is common to both A and B, use <repeated Identity> method by multiplying ratio (2) 2x

Shaded Area : Area of B

**** 8 ******* : *** 10 ***** -- (3)

In triangle A, Unshaded A = 13u - 8u = 5u

In triangle B, Unshaded B = 10u - 8u = 2u

Total Unshaded area (A,B ) = 5u + 2u = 7u

Hence,

Shaded Area : Total Unshaded Area

**** 8 ******* : ********* 7

Ans: **8 : 7**

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Trust this helps .

Do let me know again if these are different from your Answerkey or if there's further clarification.

Both questions are pretty typical kind and are not that difficult to do. I suggest that you have more practices with such questions to get familiar with the techniques . That will definitely help you to improve.

Cheers,

Edward