We are given that a certain plumber charges $92 for each job completed in 4 hours or less and $23 per hour for each job completed in more than 4 hours. We are also given that it took the plumber a total of 7 hours to complete two separate jobs, and we need to determine the total amount the plumber charged for the two jobs.

Statement One Alone:

The plumber charged $92 for one of the two jobs.

We see that the job for which he charged $92 could be 1, 2, 3, or even 4 hours long, which means the other job was 6, 5, 4, or 3 hours, respectively. Thus, we cannot determine the total amount charged for the two jobs. Statement one alone is not sufficient to answer the question.

Statement Two Alone:

The plumber charged $138 for one of the two jobs.

We see that the job for which he charged $138 must be longer than 4 hours. Since he charges $23 per hour for a job that is longer than 4 hours, we have:

138 = 23(number of hours)

6 = number of hours

Thus, the other job must have taken 1 hour, with a cost of $92. The two jobs will cost a total of $138 + $92 = $230. Statement two is sufficient to answer the question.

Answer: B
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Since the plumber charges 92$ for less than 4 hours,
it could be for a job which finishes in 1,2,3 or 4 hours.
The additional 23$ is charged for every additional hour that the plumber works.
We have been asked to find out, how much the plumber charges for both the work.

1. The plumber charged $92 for one of the two jobs.
If the plumber charges 92$ for one of the jobs, he could have finished the work in 1 hour or 4 hours.

If he had finished the work in 1 hour, he would have 6 hours to do the other work
(making the charge for the second work 92 + 2*23= 138$)
Total(Amount charged) : 92 + 138 = 230$

However, If he had finished the work in 3.5 hours, he would have 3.5 hours to do the other work
(making the charge for the second work 92$ only)
Total(Amount charged) : 92 + 92 = 184$ Clearly insufficient

2. The plumber charged $138 for one of the two jobs.
If the plumber charges 138$ for one of the jobs, he could have finished the work in 6 hours.
Charges for the work(which lasted 6 hours) 92 + 2*23= 138$)
Total(Amount charged) : 92 + 138 = 230$
As minimum charges for any work is 92$, if it takes less then 4 hours. (Sufficient) (Option B)
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Target question: What was the total amount charged by the plumber for the two jobs?

Given: $92 for each job completed in 4 hours or less. $23 per hour for each job completed in more than 4 hours. Total work time was 7 hours

Statement 1: The plumber charged $92 for one of the two jobs
This statement doesn't FEEL sufficient, so I'll TEST some values.
There are several scenarios that satisfy statement 1. Here are two:
Case a: the plumber spent 1 hour on one job (and received $92) and spent 6 hours on the other job (at $23/hours). In this case, the TOTAL amount charged = $92 + (6)($23) = $230
Case b: the plumber spent 2 hours on one job (and received $92) and spent 5 hours on the other job (at $23/hours). In this case, the TOTAL amount charged = $92 + (5)($23) = $207
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Aside: For more on this idea of plugging in values when a statement doesn't feel sufficient, read my article: http://www.gmatprepnow.com/articles/dat ... lug-values

Statement 2: The plumber charged $138 for one of the two jobs.
This means the plumber MUST have spent more than 4 hours on this job
So, the rate charged is $23/hour
$138/23 = 6. So, the plumber spent 6 hours on this job (and received $138), which means he spent 1 hour on the other job (and received $92)
So, the TOTAL amount charged = $138 + $92 = $230
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer:

Cheers,
Brent
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A certain plumber charges $92 for each job completed in 4 hours or less and $23 per hour for each job completed in more than 4 hours. If it took the plumber a total of 7 hours to complete two separate jobs, what was the total amount charged by the plumber for the two jobs?

\(92X+28Y= Total amount\)

\(#X: No of hours spent (first 4 hours or less)
#Y: No of hours spent in addition to first 4 hours\)
From data total number of hours after finishing two jobs = 7

(1) The plumber charged $92 for one of the two jobs.
So the plumber might have done 4 hours or less in one of the two jobs
Case1: If he spent 4 hours in 1st job X=4: Y=3 for 2nd job and
Total=92 ( 1st job 4 hours) + 92 (2nd job 3 hours) = 184

Case2: if he spent 1 hour ( <4); X=4 and Y=2
Total=92 ( 1st job 1 hour) + 92(2nd job 4 hours)+23*2(Additional 2 hours)=230

Two different answers NS

St2:The plumber charged $138 for one of the two jobs.
Six hours spent on one of the projects and 1 hour on the other so case 1 from above is avoided
Total amount=230
Suff

Option B
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I - just tells us one job was done in less than 4 hours. NS.

II - tells us the exact time it took for one of the jobs. As there are only two for a given time, We can answer the question.

Answer - B

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ScottTargetTestPrep wrote:

Bunuel wrote:

A certain plumber charges $92 for each job completed in 4 hours or less and $23 per hour for each job completed in more than 4 hours. If it took the plumber a total of 7 hours to complete two separate jobs, what was the total amount charged by the plumber for the two jobs?

(1) The plumber charged $92 for one of the two jobs.
(2) The plumber charged $138 for one of the two jobs.

We are given that a certain plumber charges $92 for each job completed in 4 hours or less and $23 per hour for each job completed in more than 4 hours. We are also given that it took the plumber a total of 7 hours to complete two separate jobs, and we need to determine the total amount the plumber charged for the two jobs.

Statement One Alone:

The plumber charged $92 for one of the two jobs.

We see that the job for which he charged $92 could be 1, 2, 3, or even 4 hours long, which means the other job was 6, 5, 4, or 3 hours, respectively. Thus, we cannot determine the total amount charged for the two jobs. Statement one alone is not sufficient to answer the question.

Statement Two Alone:

The plumber charged $138 for one of the two jobs.

We see that the job for which he charged $138 must be longer than 4 hours. Since he charges $23 per hour for a job that is longer than 4 hours, we have:

138 = 23(number of hours)

6 = number of hours

Thus, the other job must have taken 1 hour, with a cost of $92. The two jobs will cost a total of $138 + $92 = $230. Statement two is sufficient to answer the question.

Answer: B

What I don't understand is he could have charged $138 in 2 ways :

1. if he worked for 1.5 hours then he will charge 92*1.5= 138 so for remaining 5.5 hrs he charged 23*5.5= 126.5 . so total charged amount will be 138+126.5=264.5$

2. he worked for 6 hrs and charged 23*6= 138 and for next 1 hr he charged 92$ so total charged amount is 92+138= 230$ .... so we are not getting any unique answer so how come statement b alone is sufficient??????

As given 4hr or less = 92$ and for each extra hr = 23 $

2 jobs = 7 hr

so, 3 combination there 7 hr = 6+ 1 , 5 + 2 & 4 + 3

1. for 1 job = 92 $

as per three combination above all three having less than 4 hr working

for example , 6 hr ,1hr combination , 1 hr = 92 & 6 hr = 92 + 23 + 23

same for other two combinations so, one answer not sufficient


2.For 1 job = 138 $

as per three combination of jobs

6,1 combination = 6 (92 + 23 + 23 =138 ) and other 1 = 92

easily identified the combination

Hence B is Corerct

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