View Full Version : maths problem

minniemouth

08-03-2015, 06:39 PM

Hi guys, struggling with this.

3 squares A, B & C.

A is 5 sq.ft. larger than B.

B is 5 sq.ft. larger than C.

What are the dimensions of A, B, & C.

Cheers.

mikeS

08-03-2015, 06:51 PM

A = 3.741 x 3.741 = 14 square feet

(Square root of 14)

B = 3 x 3 = 9 square feet

C = 2 x 2 = 4 square feet

clarettim

08-03-2015, 06:52 PM

2x2

3x3

3.741x3.741

Damn beat me to it

Imploding Turtle

08-03-2015, 06:55 PM

We all agree on B atleast.

mikeS

08-03-2015, 06:57 PM

:-)

do I win a mars bar?

1959_60

08-03-2015, 07:06 PM

Sorry, no Mars Bar.

There is no unique answer with the data given.

Any answer where A is equal to B plus 5 and B is equal to C plus 5 work.

For example...

A=15, B=10, C=5 works

A=20, B=15, C=10 works

etc, etc.

More data needed.

ClaretTony2014

08-03-2015, 07:06 PM

Here you go

http://goo.gl/ZHNCKe

Imploding Turtle

08-03-2015, 07:07 PM

Is this definitely the whole question? You could just pick any two numbers 10 sq.ft apart and work backwards.

Edit: Spelling, grammar, and not the first.

minniemouth

08-03-2015, 07:25 PM

The answer is not as simple as 5, 10,15. It's the dimensions required.

The square root of 14 was my initial thought but even at 3.7416573868 squared the answer is 14.0000000001. I'm not sure if this is acceptable for the quiz or if there is an exact answer. I'm sure some Claret genius will come in with an exact answer. Flattery gets you everywhere.

Imploding Turtle

08-03-2015, 07:33 PM

As has already been pointed out, the square roots of any three numbers separated by 5 are an anser to the question as put in the OP.

Either the question someone has given you is wrong, or you're copied the question wrong on here.

claretblue

08-03-2015, 07:46 PM

2x2

3x3

3.741x3.741

Damn beat me to it

:)

minniemouth

08-03-2015, 07:58 PM

I've shortened the full question but everything relevant is there.

Using the square roots of 10 and 15 to 10 decimal places it still isn't exact.

I think I'll go with the 4sq ft, 9sq ft and 14 sq ft.

1959_60

08-03-2015, 08:01 PM

Good luck with that minniemouth.

But you will find that there are an infinite number of correct answers with the wording of the question.

conyoviejo

08-03-2015, 08:04 PM

A bath fills in 12 min using only the hot tap,in 15 min using only the cold tap and in 20 min using the shower..How long does it take to fill using all 3 together?

dougcollins

08-03-2015, 08:04 PM

Don't tell anyone, but Pi isn't exact either. Bugger isn't it.

wherewasi

08-03-2015, 08:11 PM

4mins48seconds?

1959_60

08-03-2015, 08:19 PM

5 minutes?

conyoviejo

08-03-2015, 08:33 PM

Yes, it took 5 minutes

In 1 minute hot tap will fill 1/12th bath, cold 1/15th, shower 1/20th = total 12/60th = 1/5 x5 = 5 mins

claretblue

08-03-2015, 08:50 PM

'...Yes, it took 5 minutes...'

depends if you've got a combi boiler! B)

If you take the square root of 14, and square it, you get exactly 14. Not 14.000000000001. You only get that answer if you use a calculator that doesn't remember an infinite number of digits.

To answer the original question, even if your smallest square is 1,000 x 1,000 square feet, ie. 1,000,000 square feet, you can always make the sides just that little bit bigger and get another square with 1,000,005 square feet.

Unless you've left out some ***** information, the question must be asking for algebraic answers. So if x is the length of the side of the first square, the lengths of the sides of the three squares are

x

square root (x squared + 5)

square root (x squared + 10)

And there isn't a solution which has three whole numbers.

beddie

09-03-2015, 08:42 AM

Ehh, wen I wur a lad they med proper Mars Bars.

The Bedlington Terrier

09-03-2015, 10:14 AM

At school I was really rubbish at maths. I was so bad the maths teacher let me do the school cross country run instead. This is not helping!

Notrigsbyscat

09-03-2015, 11:03 AM

there might be some quick enough with math problems on here, but they know bugger all about physics.

Let's say that bath is in my house, and I choose to switch on the tap with the hardest force first, which is the hot tap as it fills the bath in 12 minutes. It doesn't matter what the cold and shower taps do, the force of the hot tap wins

The bath fills in 12 minutes

Notrigsbyscat

09-03-2015, 11:07 AM

1959_60 is correct. Nothing about the posed problem says the sides have to be a whole number, the possibilities are infinite

Imploding Turtle

09-03-2015, 02:02 PM

If Pete has 9 apples and Anabelle has 14 apples then how many apples does John have if he has 6 more than Michael?

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