Every month, Harriet draws three paychecks from three different jobs. The largest paycheck incurs a 35% income tax, while the other two paychecks each incur income taxes of 25%. Is the total amount of tax deducted from the three paychecks greater than 30% of the total of the paychecks before taxes?
>(1) Harriet's largest paycheck is $4,000 and her second-largest is $1,500.
>(2) Harriet's smallest paycheck is $1,000.
Alternative method:
Translate the question into percent language and try to simplify it: If Harriet has three salaries, $$x$$, $$y$$, and $$z$$ (where $$x$$ is the largest), then the taxes she pays can be translated as $$0.35 x$$ (35% of the largest), $$0.25 y$$, and $$0.25 z$$ (25% of the other two). Then 30% of her total salary can be written as $$0.3(x+y+z)$$. Now the question is if
>$$0.35 x+0.25 y+0.25 z > 0.3(x+y+z)$$
which can be reduced to
>$$0.05 x > 0.05 y + 0.05 z$$
and further reduced to
>$$x > y+z $$.
Now test the answer choices according to this inequality: Stat. (1) provides a definite answer, but Stat. (2) does not. Thus, the answer is A.
Incorrect.
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Stat. (2): Consider the extremes.
1. __Maximum__: Since now there's no upper limit to the value of the
largest and second-largest checks, you can obviously find an example
where the tax is greater than 30%: $1,001 for the second check
and $1,000,000 for the largest so that the smaller checks are
negligible.
>In this case, the tax will be very close to 35% of the
total tax, and will definitely be greater than 30%. So the answer to
the question stem is "Yes", but is it always "Yes"?
2. __Minimum__: Plug in the other
extreme, with a minimal difference between the paychecks. For example, assume the small paycheck is $1,000, the medium paycheck is $1,001, and the large check is $1,002. You can even __Ballpark__ all three checks at $1,000 each. Now calculate 30% of the total:
>>$$\text{Total} = \$1{,}000+\$1{,}000+\$1{,}000=\$3{,}000$$
>>$$30\% \text{ of Total} = 30\% \times \$3{,}000 = \$900$$
>Now calculate the total tax:
>>$$\text{Tax for largest check} = 35\% \text{ of } \$1{,}000 = \$350$$
>>$$\text{Tax for other checks} = 25\% \text{ of } (\$1{,}000+\$1{,}000) = \$500$$
>>$$\text{Total tax} = \$500+\$350 = \$850$$
>This is _not_ greater than $900, giving an answer of "No."
Thus, there's no single answer, and **Stat.(2) → Maybe → IS → ACE**.
Incorrect.
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Stat.(1): The second-largest check is $1,500, so the third-largest
check can be anywhere from zero to $1,500. Plug in the extremes:
1. __Maximum__: If the third check is $1,500, then the total is
>>$$\text{Total} = \$4{,}000+\$1{,}500+\$1{,}500=\$7{,}000$$.
>Now calculate 30% of this using 10% blocks:
>>$$30\% \text{ of Total} = 30\% \times \$7{,}000 = \$2{,}100$$
>So the question is now whether the total tax is greater than $2,100.
>>$$\text{Tax for largest check} = 35\% \text{ of } \$4{,}000 = \$1{,}400$$
>>$$\text{Tax for other checks} = 25\% \text{ of } (\$1{,}500+\$1{,}500) = \$750$$
>>$$\text{Total tax} = \$1{,}400+\$750 = \$2{,}150$$
>Since this is more than $2,100, the answer to the question stem is "Yes."
Is it always "Yes"? Test it by plugging in the other extreme:
2. __Minimum__: Try zero dollars for the smallest check (or $1, close to zero). First find 30% of the total tax:
>>$$\text{Total} = \$4{,}000+\$1{,}500+\$0=\$5{,}500$$
>>$$30\% \text{ of Total} = 30\% \times \$5{,}500 = \$1{,}650$$
>Now calculate the total tax:
>>$$\text{Tax for largest check} = 35\% \text{ of } \$4{,}000 = \$1{,}400$$
>>$$\text{Tax for other checks} = 25\% \text{ of } (\$1{,}500+\$0) = \$375$$
>>$$\text{Total tax} = \$1{,}400+$375 = \$1{,}775$$
>This is still greater than $1,650, the 30% target.
Thus, the answer is always "Yes," so **Stat.(1) → Yes → S → AD**.
Correct.
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Stat.(1): The second-largest check is $1,500, so the third-largest
check can be anywhere from zero to $1,500. Plug in the extremes:
1. __Maximum__: If the third check is $1,500, then the total is
>>$$\text{Total} = \$4{,}000+\$1{,}500+\$1{,}500=\$7{,}000$$.
>Now calculate 30% of this using 10% blocks:
>>$$30\% \text{ of Total} = 30\% \times \$7{,}000 = \$2{,}100$$
>So the question is now whether the total tax is greater than $2,100.
>>$$\text{Tax for largest check} = 35\% \text{ of } \$4{,}000 = \$1{,}400$$
>>$$\text{Tax for other checks} = 25\% \text{ of } (\$1{,}500+\$1{,}500) = \$750$$
>>$$\text{Total tax} = \$1{,}400+\$750 = \$2{,}150$$
>Since this is more than $2,100, the answer to the question stem is "Yes."
Is it always "Yes"? Test it by plugging in the other extreme:
2. __Minimum__: Try zero dollars for the smallest check (or $1, close to zero). First find 30% of the total tax:
>>$$\text{Total} = \$4{,}000+\$1{,}500+\$0=\$5{,}500$$
>>$$30\% \text{ of Total} = 30\% \times \$5{,}500 = \$1{,}650$$
>Now calculate the total tax:
>>$$\text{Tax for largest check} = 35\% \text{ of } \$4{,}000 = \$1{,}400$$
>>$$\text{Tax for other checks} = 25\% \text{ of } (\$1{,}500+\$0) = \$375$$
>>$$\text{Total tax} = \$1{,}400+$375 = \$1{,}775$$
>This is still greater than $1,650, the 30% target.
Thus, the answer is always "Yes," so **Stat.(1) → Yes → S → AD**.
Stat. (2): Again, consider the extremes.
1. __Maximum__: Since now there's no upper limit to the value of the
largest and second-largest checks, you can obviously find an example
where the tax is greater than 30%: $1,001 for the second check
and $1,000,000 for the largest so that the smaller checks are
negligible.
>In this case, the tax will be very close to 35% of the
total tax, and will definitely be greater than 30%. So the answer to
the question stem is "Yes", but is it always "Yes"?
2. __Minimum__: Plug in the other
extreme, with a minimal difference between the paychecks. For example, assume the small paycheck is $1,000, the medium paycheck is $1,001, and the large check is $1,002. You can even __Ballpark__ all three checks at $1,000 each. Now calculate 30% of the total:
>>$$\text{Total} = \$1{,}000+\$1{,}000+\$1{,}000=\$3{,}000$$
>>$$30\% \text{ of Total} = 30\% \times \$3{,}000 = \$900$$
>Now calculate the total tax:
>>$$\text{Tax for largest check} = 35\% \text{ of } \$1{,}000 = \$350$$
>>$$\text{Tax for other checks} = 25\% \text{ of } (\$1{,}000+\$1{,}000) = \$500$$
>>$$\text{Total tax} = \$500+\$350 = \$850$$
>This is _not_ greater than $900, giving an answer of "No."
Thus, there's no single answer, and **Stat.(2) → Maybe → IS → A**.