guygmat wrote:

At a conference, the only events scheduled for the day are seminars and breaks. All seminars are the same length and are 10 times as long as each break. A break must be between two consecutive seminars. If the first seminar begins at 9:00 a.m. and the third one ends at 11:40 a.m., how long will the conference last if there are a total of 6 seminars that day?

A)5 hours and 15 minutes

B)5 hours and 20 minutes

C)5 hours and 25 minutes

D)5 hours and 30 minutes

E)5 hours and 35 minutes

We can let x = the length, in minutes, of a break; thus, 10x = the length, in minutes, of a seminar. Since the first seminar begins at 9:00 am and the third one ends at 11:40 am, the time elapsed is 2 hours 40 minutes, or 160 minutes. This means that the total length of 3 seminars and 2 breaks is 160 minutes. We can translate this into an equation:

3(10x) + 2x = 160

32x = 160

x = 5

So each break is 5 minutes long and each seminar is 5(10) = 50 minutes long. If a day has a total of 6 seminars, it will have 5 breaks and, thus, a day of 6 seminars and 5 breaks will last

6(50) + 5(5) = 325 minutes = 5 hours 25 minutes

Answer: C

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