Loan X has a principal of $x and a yearly simple interest rate of 4%. Loan Y has a principal...
GMAT Two Part Analysis : (TPA) Questions
Loan X has a principal of \(\$\mathrm{x}\) and a yearly simple interest rate of \(4\%\). Loan Y has a principal of \(\$\mathrm{y}\) and a yearly simple interest rate of \(8\%\). Loans X and Y will be consolidated to form Loan Z with a principal of \(\$(\mathrm{x} + \mathrm{y})\) and a yearly simple interest rate of \(\mathrm{r}\%\), where \(\mathrm{r} = \frac{4\mathrm{x} + 8\mathrm{y}}{\mathrm{x} + \mathrm{y}}\).
Select a value for x and a value for y corresponding to a yearly simple interest rate of \(5\%\) for the consolidated loan. Make only two selections, one in each column.
Phase 1: Owning the Dataset
Visualization: Weighted Average on Number Line
4% -------|----------- 5% -----------|------- 8% Loan X r Loan Y (weight: x) (weight: y)
The consolidated rate r is the weighted average of the two individual rates, where the weights are the loan principals.
Given Information:
- Loan X: principal = $x, rate = 4%
- Loan Y: principal = $y, rate = 8%
- Consolidated Loan Z: principal = $(x+y), rate = r%
- Formula: \(\mathrm{r = \frac{4x + 8y}{x + y}}\)
Phase 2: Understanding the Question
We need to find values of x and y from the given choices such that r = 5%.
Setting up the equation:
\(\mathrm{5 = \frac{4x + 8y}{x + y}}\)
Multiplying both sides by (x + y):
\(\mathrm{5(x + y) = 4x + 8y}\) \(\mathrm{5x + 5y = 4x + 8y}\) \(\mathrm{5x - 4x = 8y - 5y}\) \(\mathrm{x = 3y}\)
Key insight: For a 5% consolidated rate, the principal of Loan X must be exactly 3 times the principal of Loan Y.
Phase 3: Finding the Answer
Since \(\mathrm{x = 3y}\), let's check which value from our choices can be y:
If \(\mathrm{y = \$32,000 \rightarrow x = 3 \times \$32,000 = \$96,000}\)
Checking if $96,000 is in our choices: Yes! ✓
? Stop here - we found our answer.
Verification (use calculator for precision):
\(\mathrm{r = \frac{4 \times 96,000 + 8 \times 32,000}{96,000 + 32,000}}\)
\(\mathrm{r = \frac{384,000 + 256,000}{128,000}}\)
\(\mathrm{r = \frac{640,000}{128,000}}\)
\(\mathrm{r = 5}\) ✓
Phase 4: Solution
Final Answer:
- x = $96,000
- y = $32,000
These values satisfy the relationship \(\mathrm{x = 3y}\) and produce a consolidated interest rate of exactly 5%.