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Ratio, SM-Bank 037 MC

Tony is making a fruit cake.

The recipe says he needs 3 cups of sultanas for every 5 cups of flour.

If 2.5 cups of flour are used, how many cups of sultanas are needed?
 

  1. \(0.5\ \text{cups}\)
  2. \(1.5\ \text{cups}\)
  3. \(2.5\ \text{cups}\)
  4. \(4.5\ \text{cups}\)
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\(B\)

Show Worked Solution

\(\text{Strategy 1:}\)

\(2.5\ \text{ is half of }\ 5\ \text{cups of flour, therefore half of}\)

\(3\ \text{cups of sultanas is required.}\)

\(\rightarrow\ 1.5\text{ cups of sultanas needed.}\)

 

\(\text{Strategy 2:}\)

\(\text{Let}\ \ n = \text{cups of sultanas needed}\)

\(\dfrac{n}{2.5}\) \(=\dfrac{3}{5}\)
\(\therefore \ n\) \(=\dfrac{3\times 2.5}{5}\)
  \(=1.5\ \text{cups}\)

 
\(\Rightarrow\ B\)