Simple Maths Question (part 2)

[dr_gn]

From the same SATS question book as this:

https://www.pistonheads.com/gassing/topic.asp?h=0&...

This time an ambiguous question, no doubt (I get at least three interpretations), but what answer(s) do we get for this one?

[dr_gn]

It says “overlap” by 0.5m per bit of rope which to me doesn’t mean you lose 1m per join.

Plus...do you tie them in a line, or a circle?

[dr_gn]

Bill said:

dr_gn said:

It says “overlap” by 0.5m per bit of rope which to me doesn’t mean you lose 1m per join.

Why not? And why would you tie them in a circle?

It's not perfectly worded, but (like the other question) it's clear what they're after. I think you're over-complicating things.

No, “overlap” to me means you effectively put them end-to-end, then push them together by 0.5m. Each bit of rope then loses only 0.5m in the overlap (presumably in forming a knot) Therefore you effectively lose only 0.5m of overall length per “overlap”.

If it said “each piece loses 0.5m in the knot per join” only then would it lose 1m per join.

[dr_gn]

CaptainSlow said:

dr_gn said:

If it said “each piece loses 0.5m in the knot per join” only then would it lose 1m per join.

It does.

Where exactly does it say that?

[dr_gn]

CaptainSlow said:

dr_gn said:

Where exactly does it say that?

The second sentence says exactly that. Anyhow, what is the answer?

It says there is an overlap of 0.5m, not that you lose 0.5m per piece in the join. Two different results.

What is the answer? Depends on the question I guess?

[dr_gn]

CaptainSlow said:

dr_gn said:

CaptainSlow said:

dr_gn said:

Where exactly does it say that?

The second sentence says exactly that. Anyhow, what is the answer?

It says there is an overlap of 0.5m, not that you lose 0.5m per piece in the join. Two different results.

What is the answer? Depends on the question I guess?

It says you lose 0.5 overlap per rope...ie per piece. Assume the answer doesn't support your interpretation.

It actually doesn’t say that at all.

It doesn’t say you “lose” anything, anywhere in the question. You’re adding a word to support your interpretation, whereas I’m just answering the question.

It simply says they overlap by 0.5m per piece. For all we know, “tied” could mean joined in parallel with bits of string, or a knot in the middle of the 0.5 overlaps.

[dr_gn]

Hang On said:

The question is not ambiguous in any way. Nor is the answer. The answer is 48m. It does not matter how the ropes are joined, glued, knotted etc.

The distance between the start of the structure and the mid-point of the first joint is 9.75m; similarly the distance between the mid-point of the last join and the end of the chain.

The distance between the intermediate midpoints of the joins is 9.5m

The length of the structure is (2*9.75)+(3*9.5) = 48

Period.

ETA: cross-posted with above (correct) depiction.

Thank you.

Now let’s say we’ve got 2 cakes...

[dr_gn]

CaptainSlow said:

Your picture shows only one rope overlapping.

What on Earth are you on about?

[dr_gn]

Answer in the book is:



Again, like the cake fraction question, it’s the wrong answer to the question asked.

In both cases I can see what they were wanting to achieve, but in trying to put the question into real-world context, they screwed up the English.

[dr_gn]

Fast and Spurious said:

Hang On said:

The question is not ambiguous in any way. Nor is the answer. The answer is 48m. It does not matter how the ropes are joined, glued, knotted etc.

The distance between the start of the structure and the mid-point of the first joint is 9.75m; similarly the distance between the mid-point of the last join and the end of the chain.

The distance between the intermediate midpoints of the joins is 9.5m

The length of the structure is (2*9.75)+(3*9.5) = 48

Period.

ETA: cross-posted with above (correct) depiction.

It clearly says the ropes are tied

Yes, and if they’re tied like this, as per the question (an overlapping join), then the answer is clearly NOT 46m



For the hard of thinking: substitute rope for the steel bar.

[dr_gn]

boyse7en said:

DamienB said:

Christ, am I the only person thinking the answer is just 5 x 10 = 50m? I don't give a st how you tie them together, their total length should not be subject to the angle at which any particular portion of the rope is lying at. I paid for 5 x 10 and I've got 5 x 10.

How are you going to tie five lengths of 10m rope together to get 50m??? They would have to be laid end to end, which means you have nothing to tie together.

Tie them in triple granny knots if you like, total length of rope is still 50m cos you’ve not cut it and thrown anything away. It’s just not a continuous length of 50m.