color(green)("$2.20 candy amount is "4"lb" #### Explanation: There are two ways of solving this. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ $\textcolor{b l u e}{\text{Method 1}}$$\textcolor{B r o w n}{\text{Straight line graph approach}}$Standard form equation$\text{ } \to y = m x + c$In this case:$\text{ "c=1.2"; "m=(2.20-1.20)/100 = 1/100"; } y = 1.60$$1.6 = \frac{x}{100} + 1.2$$x = \left(1.6 - 1.2\right) \times 100 \text{ } \textcolor{p u r p \le}{\to x = 0.4 \times 100}$x=40-> 40% '~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ $\textcolor{b l u e}{\text{Method 2}}$$\textcolor{B r o w n}{\text{Ratios, which is the same thing as method 1 just that this fact is in disguise.}}$The approach is based on the principle that the gradient is constant. $\frac{100}{2.2 - 1.2} = \frac{x}{1.6 - 1.2}$Basically this is saying that the gradient of the whole is the same gradient as part of it! $\frac{100}{1} = \frac{x}{0.4}$$\textcolor{p u r p \le}{0.4 \times 100 = x}$x=40" " -> 40% $\textcolor{g r e e n}{' \text{NOTE THAT IS 40% OF THE $2.20 CANDY}}$
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$\textcolor{b l u e}{\text{Determine the weights of each constituent}}$

so 100%-40% =60% as the proportion of the $1.20 candy Let the whole weight be $w$then $\frac{60}{100} w = 6$$w = \frac{6 \times 100}{60} \text{ "=" "100/10" "=" } 10 l b$So color(green)("$1.20 candy amount is "6"lb"
color(green)("\$2.20 candy amount is "10-6 = 4"lb"