Ruth began a job

[sanju09]

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.


[spoiler]Source: https://gmat.practicetests.teachstreet.com[/spoiler]

[niksworth]

A

Statement 1:
She began the job at 8.15 am. Time elapsed till noon - 3hr 45 min. By this time she had completed half the job. So time taken to complete the job is a further 3 hr 45 min. So job was finished at 3.45 pm

Statement 2:
We do not know when she started, so we cannot calculate the end time.
Thus 1 alone is sufficient but 2 alone is not sufficient. Hence answer is A.

[Maciek]

Hi!

thank you for posting questions on beatthegmat,com, Sanju09.

(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.

12 h - 8 h - 15 min = 3 h 45 min

3 h 45 min it is half of her working time

full period of time is twice as much as 3 h 45 min. It is 7 h 30 min

she had finished job at 3:45 p.m.

this statement ALONE is SUFFICIENT so answer should be A or D

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

we can't answer the question because we don't know when she started the job

so it is INSUFFICIENT

IMO A

hope it helps!