### Viva Question 6

Question 6 :
a) i) a:b = 1 1/2 : 2 2/5
= 1.5 : 2.4
-changed to nearest whole number-
= 30 : 48
-simplified-
= 15 : 24
= 5 : 8

ii) b:c = 0.105 : 0.350
-changed to whole number-
= 105 : 350
-simplified-
= 21 : 70
= 3 : 10

b) a:b = 5:8
b:c = 3:10
Since 'b' is the repeated value in both ratios , the ratios have to be multiplied so that the value of 'b' will be the same in both ratios .
a:b = 15:24
b:c = 24:80
a:b:c = 15:24:80

c) a+b+c = 119 units
\$500 ÷ 119 * 15 ( Alan's share in units )
≈ \$63.03 (2 d.p)

1. mathematical terms [1]
explanation of working/solution must be clear [3]
understanding of concept [2]
presentation [1]
- you are pointing to the different mathematical statement that you are explaining.
- there is some background noise and the video is a little jerky

2. Presentation [1/2]
-She was pointing at the wrong part of the solution while she was explaining another part.

Mathematical terms [1/1]

Explanation of working/solution must be clear [2/3]
-She said '8/10' for part (b), when it was supposed to be '3/10'

Understanding of concepts [2/2]

Total: 8/10

3. Note: Comments are made reference to the clip copied submitted separately (offline).

PS: @DYS (Gladys?) @Jonathan - the misalignment was due to errors when clip uploaded online.

1. For (a),
in (i) you mentioned the the ratio "is also equal to 1.5 is to 2.4". Why? Will need to elaborate why changing them to decimals first. Why convert to the nearest who number? How to get "30 is to 48"? Also, good to explain how to go about simplifying? Say, we find the highest common factor of the 2 numbers and divide both numbers by HCF so as to express ratio in its simpest form.