Question

Difficulty: Very hardFractions, Decimals, and Percentages

Four investment options, each with a different starting value (expressed as a fraction, decimal, or percentage of a standard initial budget BB) and a specified first-year growth rate, are described below. Arrange the options in order from the lowest final value to the highest final value after the first year.

  1. 1Option Y: A starting value of 90%90\% of BB that increases by 15%15\%.
  2. 2Option Z: A starting value of 78\frac{7}{8} of BB that increases by 18.4%18.4\%.
  3. 3Option X: A starting value of 0.850.85 of BB that increases by 22%22\%.
  4. 4Option W: A starting value of 45\frac{4}{5} of BB that increases by 30%30\%.

Answer

Option Y, Option Z, Option X, Option W
The correct order is Option Y, Option Z, Option X, Option W. Converting each initial value to a decimal fraction of BB and applying the respective growth multipliers yields: Option Y is 0.90×1.15=1.035B0.90 \times 1.15 = 1.035B, Option Z is 0.875×1.184=1.036B0.875 \times 1.184 = 1.036B, Option X is 0.85×1.22=1.037B0.85 \times 1.22 = 1.037B, and Option W is 0.80×1.30=1.040B0.80 \times 1.30 = 1.040B. Comparing these decimal values gives 1.035<1.036<1.037<1.0401.035 < 1.036 < 1.037 < 1.040.

Step-by-Step Solution

1
Calculate the final value of Option W relative to BB.
0.80×1.30×B=1.040B0.80 \times 1.30 \times B = 1.040B
Convert the starting fraction 45\frac{4}{5} to the decimal 0.800.80. A 30%30\% increase corresponds to a multiplier of 1+0.30=1.301 + 0.30 = 1.30. Multiply these values together: 0.80×1.30=1.0400.80 \times 1.30 = 1.040.
2
Calculate the final value of Option X relative to BB.
0.85×1.22×B=1.037B0.85 \times 1.22 \times B = 1.037B
The starting decimal is 0.850.85. A 22%22\% increase corresponds to a multiplier of 1+0.22=1.221 + 0.22 = 1.22. Multiply these values together: 0.85×1.22=1.0370.85 \times 1.22 = 1.037.
3
Calculate the final value of Option Y relative to BB.
0.90×1.15×B=1.035B0.90 \times 1.15 \times B = 1.035B
Convert the starting percentage 90%90\% to the decimal 0.900.90. A 15%15\% increase corresponds to a multiplier of 1+0.15=1.151 + 0.15 = 1.15. Multiply these values together: 0.90×1.15=1.0350.90 \times 1.15 = 1.035.
4
Calculate the final value of Option Z relative to BB.
0.875×1.184×B=1.036B0.875 \times 1.184 \times B = 1.036B
Convert the starting fraction 78\frac{7}{8} to the decimal 0.8750.875. An 18.4%18.4\% increase corresponds to a multiplier of 1+0.184=1.1841 + 0.184 = 1.184. Multiply these values together: 0.875×1.184=1.0360.875 \times 1.184 = 1.036.
5
Compare the resulting multipliers to order the final values from lowest to highest.
1.035<1.036<1.037<1.0401.035 < 1.036 < 1.037 < 1.040, which translates to Option Y < Option Z < Option X < Option W.
By arranging the computed multipliers in ascending order, we find the correct sequence.

Key Concept

Converting fractions, decimals, and percentages to common decimal representations to compute and compare multi-step percentage increases.
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