### (Viva Voce) Chap 9 Exercise 9 Question {6}

a     :     b
1 1/2 : 2 2/5
1.5  :  2.4
30  :   38
5   :    8

a     :     b     :     c
5     :     8     :     c
a     : 0.105  : 0.350
a     :   105   :   350
a     :     3      :   10
15    :    24     :    80

15+24+80 = 119

alan : 15/119 * \$500 \$63.03 (2dp)

#### 3 comments:

1. Mathematical Terms [1]
Explanation of working [3]
Understanding of concepts [2]
Accuracy of answer [2]
Presentation [1] The words are a bit blur .

2. Presentation [1/2]
-The words are a bit blur, and a shadow is covering a part of the paper.
Mathematical terms [1/1]
Explanation of working [3/3]
Understanding of concepts [2/2]
Accuracy of answer [2/2]

Total: 9/10

3. 1. Explanation of the conversion steps is clear. However, why do we need to convert? Also, how to go about simplifying the ratio to become "5 is to 8"? i.e. by identifying the highest common factor and therefore divide the 2 numbers by the HCF.

2. I think you've left out (ii), but included that in your explanation for (b)?

3. You've explained how to make "b" in both ratios having the same number of parts. However, why do we need to make them into the same number of parts? Also, how did you arrive at those 'magic' numbers to multiply to the 2 ratios?

4. Explanation for (c) is very clear.

5. The use of pencil to guide the viewer is helpful :)