California C-10 exam question

[catronics]

Greeting to everyone, this is my first post.

I'm studying for my California C-10 exam this month.

I'm stumped, and now I'm downright curious about an exam question. I'm using some sample practice exams that I bought from a business called Contractors State License Schools, which is a contractors exam prep school here in California. (I'm presuming they've used spies to find out what the questions are over a long period of time, or something like that.)

I've use one of these schools before, and I've learned that sometimes, when I think the school is giving me a really wacky question, it turns out that the doggone Contractors State License Board really does ask that question. Here's the one I'm scratching my head about:

"In a school, twenty 75-watt incandescent lights were replaced with twenty 20-watt fluorescent bulbs. If they pay $0.10/KWH, how much will they save in a year?"

At 55 W savings and 20 bulbs, which is 1.1 kW, there is a savings of $.11 an hour. Great! No problem!

But how many hours does the school run their lights? Since the answer is $275, it calculates out to 2500 hours. Does anybody know how many hours a school has their lights on? There's security lights and gym lights and hallway lights and office lights, and then there's special events, etc. Why do they ask this question without more information? Math I can do. But I need more data. Grr. :?

Any advice?

 

[Fulthrotl]

Greeting to everyone, this is my first post.

I'm studying for my California C-10 exam this month.

I'm stumped, and now I'm downright curious about an exam question. I'm using some sample practice exams that I bought from a business called Contractors State License Schools, which is a contractors exam prep school here in California. (I'm presuming they've used spies to find out what the questions are over a long period of time, or something like that.)

I've use one of these schools before, and I've learned that sometimes, when I think the school is giving me a really wacky question, it turns out that the doggone Contractors State License Board really does ask that question. Here's the one I'm scratching my head about:

"In a school, twenty 75-watt incandescent lights were replaced with twenty 20-watt fluorescent bulbs. If they pay $0.10/KWH, how much will they save in a year?"

At 55 W savings and 20 bulbs, which is 1.1 kW, there is a savings of $.11 an hour. Great! No problem!

But how many hours does the school run their lights? Since the answer is $275, it calculates out to 2500 hours. Does anybody know how many hours a school has their lights on? There's security lights and gym lights and hallway lights and office lights, and then there's special events, etc. Why do they ask this question without more information? Math I can do. But I need more data. Grr. :?

Any advice?

.
i'd take the delta, which is 11 cents an hour, and find out which answer
that they offer divides evenly, and does it appear reasonable?

it's a math question, not a sparky question.

if it were a sparky question, it would be.... after installing and commissioning
the prescribed title 24:2016 measure, how long will it take to recover the cost
of the LED lights, and $37,845 worth of lighting controls?

(there is no correct answer, as it will never happen.)

if it were a contractor question, it would be.... how long till i get the retention
off of this damn job? it's been done six months now.....

(correct answer: 27 months.)

welcome to the forum.

the easiest way to do this, is to find a "school" that offers online practice testing,
and just loop the questions till you can hold an 85% score, then go in and test.

the one i used was at 1 800 480 7277. dunno if they are still alive or not.
you signed up for classes on site, and the online practice test. i never went
back for the classes, i just looped the practice till it held at 85%, then went
and sat for the test.

edit: i'm pretty sure these guys are defunct. i've still got all my practice info,
scanned into a pdf. send me a private message if you want it.

there is also a wealth of info on mikeholt.com.... the fellow who graciously
puts up the server for this forum to run on. i'd shop there.

 

[GoldDigger]

That looks like a particularly badly designed question.
2500 hours is about 6.8 hours/day for a 7 day week or 9.6 hours per day for a 5 day week.
Is the school in session during the summer?
Etc. .....

 

[ramsy]

"In a school, twenty 75-watt incandescent lights were replaced with twenty 20-watt fluorescent bulbs. If they pay $0.10/KWH, how much will they save in a year?"

Got $280.5. 10-hrs per day, 30-days a month, for 8.5 months.
Schools don't run the whole year. Don't count summer months, or the 2-week Xmass holiday.
Since its common knowledge that exploited teachers burn lights 2-extra hours w/out pay, added 2-hours to normal 8-hr day.

 

[GoldDigger]

Got $280.5. 10-hrs per day, 30-days a month, for 8.5 months.
Schools don't run the whole year. Don't count summer months, or the 2-week Xmass holiday.
Since its common knowledge that exploited teachers burn lights 2-extra hours w/out pay, added 2-hours to normal 8-hr day.

You forgot about summer school and night classes for adult education.

 

[catronics]

Thanks for the friendly reply, and funny too. Thanks. Yes, that is exactly what I am doing, just taking and retaking and retaking the exams that they have. There are four exams and my goal is to take them until I get 90% on all of them. I'm zipping along so far!

And yeah, some of the stuff just doesn't make sense. I'll just jam it into my brain and hope for the best!

Thanks, everyone, for the help!

 

[jaggedben]

@catronics
Your school forgot to copy part of the question into their instruction materials, or else the sample question mailed to some applicant which they copied (that's where the schools get these) was incomplete. Either that, or they copied a trial question. Some questions are trial questions that don't actually count when you take the exam, but the CSLB is trying them out to see how people answer and if they are appropriate for later versions.

When you take the exam, there's a place where you can put comments on the questions. If you actually get a question this stupid, put a comment that the info in the question is incomplete. If it's trial question, it won't matter, and if you fail the exam it may give you a basis to challenge the result if that or similar questions are the only question you got 'wrong'.

 

[Jraef]

Was it multiple choice? The reason I ask is because often you can deduce the correct answer by determining which of the other choices are obviously not going to be correct.

For example:

A: $1070.00
B: $275.00
C: $13.00
D: $688.00

So knowing that it is 11 cents/H saved;

1070/.11= 9727 hours = 26 hrs per day even if it was 365 days, can't be that
13/.11 = 118 hours, you can safely assume a school is open more than 118hrs/year.
688/.11 = 6254 hours, so even at 10 hrs/day, that's 625 days, can't be that.

Ergo, 275 it is...

 

[Sierrasparky]

There is a guy on this forum who usually attends the CSLB test writing workshop for the new C-10 exams.
Maybe he will chime in.
I really find it hard to believe that the CSLB is now testing the C-10 for energy codes which they dismiss as foolish and silly.

 

[jaggedben]

Was it multiple choice? The reason I ask is because often you can deduce the correct answer by determining which of the other choices are obviously not going to be correct.

For example:

A: $1070.00
B: $275.00
C: $13.00
D: $688.00

So knowing that it is 11 cents/H saved;

1070/.11= 9727 hours = 26 hrs per day even if it was 365 days, can't be that
13/.11 = 118 hours, you can safely assume a school is open more than 118hrs/year.
688/.11 = 6254 hours, so even at 10 hrs/day, that's 625 days, can't be that.

Ergo, 275 it is...

How do you know that the lights aren't in rarely used closets such that (C) makes sense? In my opinion it's just a bogus question without usage info. CLSB shouldn't be teaching contractors to just make assumptions when information is lacking. That is unless the lacking information is precisely what you're being tested on, e.g. an energy code standard that estimates school lighting usage.

 

[infinity]

Isn't it possible that they simply left the 2500 hours out of the question by mistake?

 

[jaggedben]

Isn't it possible that they simply left the 2500 hours out of the question by mistake?

Yeah well that's what I speculated in post 7.