Sofia will attend a sequence of daily training sessions

[Needgmat]

Sofia will attend a sequence of daily training sessions for her job. On the last day of her training sessions she will attend either 1 session or 2 sessions. On each of the other days of her training sessions she will attend exactly 2 sessions. At the end of her third day of attending training sessions, how many sessions will Sofia have left to attend?

1) The sequence of training sessions Sofia will attend will last 6 days.

2) There are a total of 11 training sessions in the sequence of training sessions Sofia will attend.

OAB

Please explain.

[DavidG@VeritasPrep]

Sofia will attend a sequence of daily training sessions for her job. On the last day of her training sessions she will attend either 1 session or 2 sessions. On each of the other days of her training sessions she will attend exactly 2 sessions. At the end of her third day of attending training sessions, how many sessions will Sofia have left to attend?

1) The sequence of training sessions Sofia will attend will last 6 days.

2) There are a total of 11 training sessions in the sequence of training sessions Sofia will attend.

OAB

Please explain.

Statement 1: Case 1 - Sofia attends 1 session on the last day and 2 on the other 5, for a total of 1 + 5*2 = 11. At the end of the third day, she'd have attended 6 sessions, leaving another 5.

Case 2 - Sofia attends 2 session on the last day and 2 on the other 5, for a total of 2 + 5*2 = 12 At the end of the third day, she'd have attended 6 sessions, leaving another 6.
Not Sufficient

Statement 2: After three days, she'd have attended 6 sessions. That would leave 5 more sessions. Only one possibility, so this statement alone is sufficient.

Answer is B

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Hi Needgmat,

While this prompt is wordy, the information that it offers is relatively simple:
1) Sofia is attending a series of daily training sessions for an unknown number of days.
2) She will attend 2 sessions per day EXCEPT for the LAST DAY (she will attend either 1 or 2 sessions on that day).

The question asks how many sessions Sofia has remaining after the first 3 days have passed.

1) The sequence of training sessions Sofia will attend will last 6 days.

This Fact tells us that Sofia has 3 days remaining (since she already did the first 3 days and there are 6 days in total. That means she has either 5 or 6 sessions remaining (depending on the last day) - but we don't know for sure whether it's 5 or 6.
Fact 1 is INSUFFICIENT

2) There are a total of 11 training sessions in the sequence of training sessions Sofia will attend.

We know that Sofia already did 6 sessions (over the first 3 days), so she has 5 sessions remaining. By extension, that means that the remaining days will consist of exactly 2, 2 and 1 sessions respectively.
Fact 2 is SUFFICIENT

Final Answer: B

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