Posted by Jane on Monday, April 29, 2013 at 8:51pm.
Alyssa is enrolled in a public-speaking class. Each week she is required to give a speech of greater length than the speech she gave the week before. The table below show the length of several of her speeches:
WK #/Length of Speech (seconds)
3/150, 4/180, 5/210, 6/240
If this trend continues, in which week will she give a 12-minute speech?
By converting 12 minutes to 720 seconds and going week by week, I chose 22.
How do I set this up as a problem and solve it? Thanks
- math - Reiny, Monday, April 29, 2013 at 9:53pm
each week she increases her speech by 30 seconds
12 minutes = 720 seconds
(you are right so far)
This is an arithmetic sequence, where
a = 150 , d = 30
we need to find which term is 720
150 + (n-1)(30) = 720
30n - 30 = 570
30n = 600
n = 20
but what I considered first term is really the third term (3rd week)
so she reaches the 12 minute speech in week 22
You are right!
- math - allah, Friday, May 13, 2016 at 2:48pm
this answer^ is bull
- math - allah akbar, Friday, May 13, 2016 at 2:50pm
the correct answer is actually Alyssa is a satanist and she will die before the last speech which is 12 minutes...
Answer This Question
More Related Questions
- Public Speaking - Evaluating audience feedback to your speech presentation ...
- English - What would the following time expressions change to in reported speech...
- public speaking - 1. A speaker talking about the benefits of cosmetic surgery to...
- principle of public speaking - Organizing a speech means to : a)research the ...
- public speaking - Organizing a speech means to: research the materials. ...
- speech class - I have to do a speech about johnny depp next week in my speech ...
- public speaking - When preparing an outline for a speech, which of the below is ...
- Speech 09 - I had to interview someone in my class and write speech about them...
- public speaking - Paul is delivering a speech on the hunger epidemic in the ...
- public speaking - You are evaluating this when you are looking for a clear, ...