To solve the problem using a tape diagram, we can represent the allowances of Olivia and Sylvia visually. The ratio of their allowances is 2:3, which means for every 2 parts that Olivia receives, Sylvia receives 3 parts.
- Draw the Tape Diagram:
- Create two sections in the tape diagram, one for Olivia and one for Sylvia.
- Represent Olivia's allowance with 2 parts and Sylvia's allowance with 3 parts.
Olivia: [---|---]
2 parts
Sylvia: [---|---|---]
3 parts
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Total Number of Parts:
- The total number of parts in the ratio is \(2 + 3 = 5\) parts.
-
Value of Each Part:
- We know Sylvia's allowance is $21, which corresponds to the 3 parts.
- To find the value of one part, we divide Sylvia's allowance by the number of parts she represents: \[ \text{Value of one part} = \frac{21}{3} = 7 \]
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Calculate Olivia's Allowance:
- Now we can find Olivia's allowance, which is represented by 2 parts. \[ \text{Olivia's allowance} = 2 \times 7 = 14 \]
Thus, Olivia received $14 that week.