If Ruth began a job and worked continuously until she finished, at

Question

If Ruth began a job and worked continuously until she finished, at what time of day did she finish the job?

(1) She started the job at 8:15 a.m. and at noon of the same day she had worked exactly half of the time that it took her to do the whole job.

(2) She was finished exactly 7.5 hours after she had started.

Bunuel · Accepted Answer

If Ruth began a job and worked continuously until she finished, at what time of day did she finish the job?

(1) She started the job at 8:15 a.m. and at noon of the same day she had worked exactly half of the time that it took her to do the whole job --> at noon of the same day, so after 3 hours and 45 minutes she started, Ruth had worked  HALF OF THE TIME  that it took her to do the whole job, which means that the total time it took Ruth to do the whole job is 7.5 hours, so she finished the job at 8:15 a.m+7.5 hours=15:45 p.m. Sufficient.

So as you can see we are not concerned about her rate at all.

(2) She was finished exactly 7.5 hours after she had started. Not sufficient, since we don't know at what time Ruth started the job.

Answer: A.

boomtangboy · Answer

But what if she increased the rate at which she worked, then the time taken would be less. Thus we would not be able to calculate the time at which she finished Still confused :?:

Bunuel · Answer

We are told that 3 hours and 45 minutes is  HALF OF THE TIME  that it took her to do the whole job. If 3 hours and 45 minutes is half of the time then the total time it took Ruth to do the whole job is 7.5 hours.

shivanigs · Answer

Stmt 1 : The time taken from 8:15 a.m. to noon = 3 hrs 45 mins

Since this is half the time she took to complete the job,the total time taken by her to complete the job is = 6 hrs 90 mins i.e. 7 hrs 30 mins

This can help us arrive at the definite time she finished the job, hence this statement is sufficient.

Stmt 2 : While we know the total time she took to complete the job,we do not know the exact time she started working.

Since it is not possible for us to arrive at the exact time of completion,this statement is insufficient.

Answer : A

yannichc · Answer

not a massive fan of this question bcos it assumes she doesnt take any breaks, assumes a constant Rate of work - does she slow down or increase her rate?

Wish the question said no breaks and constant rate...

Bunuel · Answer

If you read the question carefully enough, you'll see that:
1. the question says: "...Ruth began a job and  worked continuously  until she finished, ... ", so no breaks there.
2. the rate does not matter at all. It's not a work/rate problem.

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If Ruth began a job and worked continuously until she finished, at

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