I’ll share how I solved this question.
As a practice, one thing I do while reading the question is scan the answer choices. I do this even before I start any mental calculations.
1:When I scanned the answer choices, I noticed (D) $240,000. It immediately stood out. Why? Because I realized that 10% of 240,000 is 24,000 (the total commission amount).
- If the commission were 10% on the entire $240,000, that alone gives $24,000.
- But in reality, the first $50,000 is charged at the higher 15%, which means the total commission would exceed $24,000 if I consider the sale price of 240,000.
- So (D). $240,000 cannot be correct.
This was a quick way to eliminate one extreme option without much calculation.
2:Now, notice something important: since 10% of $240,000 already equals $24,000, what we actually need is a value less than $240,000 so that:
- part of the price is charged at the higher 15%, and
- the rest at 10%,
... giving exactly $24,000 as the total commission.
That means any value higher than $240,000 would only push the commission further up, so we can also rule out Option E ($365,000) straight away.
So now we’re left with only A, B, and C to consider.
3:Out of A, B, and C, I picked $160,000 (Option B) next. Why? Because it neatly splits the three remaining options. With one check, I can figure out if the correct answer is exactly 160,000, below it or above it.
Now, this is where my fast mental maths helped me. I know 15x15 is 225. So, 15 x 16 would be 225 + 15 =240.
- So, if the entire $160,000 were charged at 15%, the commission would be exactly $24,000.
- But in reality, part of the price is charged at the lower 10%.
- That means if the price were 160,000 the total commission would be less than $24,000. So $160,000 is too low.
So the actual price must be greater than $160,000.
4:At this stage:
- $160,000 was too low.
- $240,000 and $365,000 were too high.
I can reject answers <= 160,000 and answers >= 240,000.
That leaves $215,000 as the only possibility.
5:(Not required. But, if you can afford the time a good idea to double-check.)
- First $50,000 @ 15% → 10% of 50,000 + half of 10% of 50,000 → 5,000 + 5,000/2 = 5,000 + 2,500 =7,500.
- Remaining: 215,000 - 50,000 = $165,000 @ 10% = $16,500
- Total commission = $7,500 + $16,500 = $24,000
Fits!