I am emailing a link of this to everyone on the class list every week. If you are not receiving these emails or want to have them sent to another email address feel free to email me at jpmccarthymaths@gmail.com and I will add you to the mailing list.
Catch-Up Tutorial for COMP 1B-X
11:00, Tuesday 11 October in D160
Assessment 1
Results out in the next few days…
Assessment 2
Assessment 2 will be on the Wednesday of Week 6, 19 October 2016.
Keep an eye on your CIT Blackboard and email for the latest and definitive assessment information.
Week 4
We looked at tax and interest as well as length and area. We started talking about trigonometry.
Week 5
We will finish off the section on trigonometry and then move onto statistics.
Study
Please feel free to ask me questions about the exercises via email or even better on this webpage.
Student Resources
Please see the Student Resources tab on the top of this page for information on the Academic Learning Centre, etc.
J.P. McCarthy: Math Page 
2 comments
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October 11, 2016 at 7:52 am
Student
Hi,
You told me to contact you regarding my questions about Assessment 1.
Regards.
October 11, 2016 at 9:10 am
J.P. McCarthy
Just commenting on what went wrong:
Your solution to question four increased something by 20% that was decreased by 20% but increasing by 20% is not the inverse of decreasing by 20%. What you should have done is seen that the September 2016 enrollment, 120, was a 20% reduction on the September 2015 enrollment and so 120 was 80% of the September 2015 enrollment. Therefore, dividing by four, 30 was 20% of the 09/15 enrollment and, multiplying by five, 150 was 100% of the 09/15 enrollment i.e. 150 was the September 2015 enrollment and thus the answer. Instead you took 120 and increased it by 20%. 20% of 120 is 24 and you did 120+24=144 but this is not the correct answer… decreasing 144 by 20% does not give 120.
In question six there were six plasterers taking 12 hours to do a job. Therefore in total there was 72 hours of work. If the work was done in 8 hours then the work was shared according to
workers each working for 8 hours gives the 72 hours. You misinterpreted the question as 6 plasters working for two hours each to make up 12 hours rather than the 6 plasterers working in parallel.
Overall, therefore you did very well on the MCQ, getting 48/60 or 80% on those.
After this things went poorly for you.
In question 11 (a) you didn’t round correct to two significant figures. Two significant figures means two non-zero numbers.
For part (i) you did
. This is rounding correct to four significant figures. It should have been 32.
For part (ii) you did
. This is rounding correct to three significant figures. It should have been 8.3.
For part (iii) you did
. This is rounding (incorrectly) to three significant figures (correct to three significant figures would be 476). It should have been 480.
You got part (iv) correct rounding
.
For Q. 11 (b) you were supposed to share out €600… your answer was €40 : €50 : €60 which is clearly incorrect as they don’t sum to €600.
You wrote the ratio as
This is correct but these don’t add up to one! You could have either added these up and divided or multiplied all by 30 to get
and proceeded from there.
You failed to read question 12 properly and your answer doesn’t really make sense.
Question 13 was fractions. You correctly got down to
As I said you did really well on the MCQ. After that you made some mistakes. In particular, not asking yourself did your answer to Q. 11 (b) make sense and not reading Q. 12 carefully.
You are not far off on 54%. I advise that you forget about Assessment 1 — realise you are doing well really — and concentrate on Assessment 2.
Regards,
J.P.