# What is the answer to this question, and why is that the answer?

Asked by Dutchess_III (45440) January 22nd, 2021

In the stock market 4 different stocks have an average cost of \$100 per stock. The price of the drone stock is \$70.
What is the average price of the 3 other stocks (not including the drone stock)?

I think the wording makes it a bit of a trick question but I think the answer is \$100.

What do you say?

Observing members: 0 Composing members: 0

\$110

Show your working out.

doyendroll (1771)

How did you come up with that @doyendroll?

Dutchess_III (45440)

I would say 100, but I suck at math.

chyna (47843)

I won’t venture an awnser. Math always gives me a headache. Not my forte.

110 if the average is 100, 4of them would total 400. The drone is 30 short of the 100 average. Divided 3 ways comes to 110. 110×3=330. 330+70=400 or an average of 100 each

stanleybmanly (24138)

How did you come up with that @stanleybmanly?

Dutchess_III (45440)

I’m all agog at your pedagogy, I use oopsimath what did you use?

doyendroll (1771)

@doyendroll and @stanleybmanly Show your work please.

chyna (47843)

I’m not explaining this well enough. If the average is 100 and the drone is 70, the drone is 30 short of average. You simply divide the 30 3 ways and add the 10 dollars to each remaining stock. 130 apiece for the 3 and 70 for the 4th— 100 is the average.

stanleybmanly (24138)

But the problem specifically excludes the drone stock.

Dutchess_III (45440)

It does not. The drone stock must be included or where’s the problem? All 4 stocks comprise the problem. The question is not asking you to exclude the drone from the question, but to exclude its PRICE from your answer.

stanleybmanly (24138)

The thing is, I would actually have to concentrate to call up the algebra. But it isn’t necessary if I can reduce it to basic arithmetic in my head. The rest of you can do it—no problem. Dutch was simply thrown off by the wording.

stanleybmanly (24138)

I figured it out. Rick first brought the problem to me verbally. Anyway, the thing I skipped over is that we’re only dealing with 4 stocks total with an AVERAGE cost of \$100. Not 4 stocks worth \$100 each, plus a 5th drone stock. No. The \$70 drone stock is part of the original fab 4. When that sinks in it’s simple.

Dutchess_III (45440)

See

stanleybmanly (24138)

Saw

Dutchess_III (45440)

@Dutchess_III misled me! I didn’t count the drone stock! :-)

chyna (47843)

I didn’t invent the problem! Rick applied for a job as a lake supervisor and the city is sending all these aptitude tests he has to take as part of the application process.
He said there is one tomorrow that focuses on the psychological aspect of the applicant. I told Rick I need to take that one for him. :D

Dutchess_III (45440)

@chyna….my son is an excellent teacher. He’s my go to for every thing. He must have had an amazing mum.
Here it is:
“4 stocks at 400. Take the 70 drone stock out= 330. 330 divided by the three left is 110.”

Dutchess_III (45440)

See? @stanleybmanly was right, Mrs Smarty-Pants.

Yellowdog (12208)

Are you a primary school teacher Dutchess?

doyendroll (1771)

Why do you ask @doyendroll?

Dutchess_III (45440)

I never argued with @stanleybmanly or suggested he was wrong @Mr Dumbass Yellowdog.

Dutchess_III (45440)

Yeah. Don’t be silly The Dutchess knows that I worship her.

stanleybmanly (24138)

Lol @Dutchess_III Why is everyone always pickin’ on Dog? ; )

Unlike any dog you will ever see, ours has a great talent for “stepping in it”, and tracking IT all over the place. He remains nevertheless OUR dog, and we take great offense at the idea of those aside from ourselves kicking and beating OUR dog.

stanleybmanly (24138)

4 stocks averaging \$100 have a total cost of 4×100 = 400. Subtract price of \$70 drone stock to get a price of 400 – 70 = 330 for the three other stocks. Average price of three other stocks is 330/3 = 110.

Here is another way of looking at it. It is a little more complex, but it allows us to set everything up as a single equation that needs to be solved for x.

It may be easier to think of these as test scores rather than dollars.

Overall test scores for four tests average 100. The drone test score is 70 points. What is the average score of the remaining tests?

The drone counts for ¼ of the overall test score, and the remaining three tests count for ¾ of the overall average. If x = average of the three other test scores we get:
¼×70 + ¾ x = 100. Solving for x will give us x=110.

The advantage of this approach is that it is rather flexible and permits the solution of more complex problems.

For example, suppose we are told that the drone price was 80% of the average of the other three stocks and that the overall average is 110. What is the price of the drone stock?
Again let x = average price of the other three stocks. The drone stock price is .8 x.
We get ¼ .8x + ¾ x = 110. Solve for x. The drone price would be .8x.

@stanleybmanly …we take great offense at the idea of those aside from ourselves kicking and beating OUR dog.

So true!

Strauss (22833)

And that reminds me once again, where’s flo?

stanleybmanly (24138)

I think she might be looking for cak in the frizzer

Strauss (22833)

So if 3(x) +70= 400, solve for x.

Now we can show the work. First let’s subtract 70 from both sides of the equation yielding:
3x=330

Divide both sides by 3, we get:
X=30

stanleybmanly (24138)

I love almost all of you! Even Doggo.

Dutchess_III (45440)

Exactly! Like the porn addicted uncle that shows up every Thanksgiving—we’re glad to see him. He’s one of us—he comes on the tour! Your family isn’t your family because they are perfect!

stanleybmanly (24138)

AAAAwwwww!

Yellowdog (12208)

We might love you, but I have absolutely no inhibition against hiding you from the neighbors. I’m not gonna lie. You will never catch me bragging to outsiders about your “eccentricities.”

stanleybmanly (24138)

LOL! Who let him out of the basement??

Dutchess_III (45440)