Best friends Olivia and Sylvia both get a weekly allowance. Olivia's and Sylvia's allowances are in the ratio 2 : 3. If Sylvia gets $21 one week, how much did Olivia get? Use a tape diagram to help organize your thinking. (1 point)
Let's represent Olivia's and Sylvia's allowances with 'O' and 'S' respectively.
Given that Sylvia gets $21 one week and Olivia's and Sylvia's allowances are in the ratio 2 : 3, we can set up the equation:
2/3 = x/21
To solve for x, we cross multiply:
3x = 2 * 21
3x = 42
x = 42/3
x = 14
Therefore, Olivia got $14.