AQA 9-1 GCSE Maths (Higher) - 2017 Paper 1 [Official Thread] 25 May

For those wanting to know about the miles to kilometres question. This is how it went

x miles : y kilometres
5 miles : 8 Kilometres

The question states write y in terms of x [2 marks]

step 1, put them in fractions as they are ratio:
This meant; x/y = 5/8
Flip all them over
y/x = 8/5

Now rearrange it, y = (8/5) x = 8x/5

Therefore it WAS y = (8x)/5

In case people don't agree: Here is metric conversions . org's results.

I put in 2 miles, which was around 3.2 kilometres.

2 miles = x miles, therefore x = 2
Put x = 2 into the equation

y = (8x2)/5 = 16/5 = 3.2 kilometres, which is near the value that the website gave me.

If it was (5x)/8 as people are saying, then 2 miles would give me (5x2)8 = 10/8 = 1.25 kilometres, which is incorrect in conversion.

(edited 6 years ago)

Reply 266

RPatel365

6

For the bottles one, I wrote the amount of money it costs for the cheapest 8, and I wrote something along the lines of 2 from shop A, and 2 for Shop B... would I lose a mark for not writing 6 bottles from shop A, what I meant with '2 from shop A' is (2 times the 3 bottles) in the deal.

Reply 267

Original post by Rian Kelly

Vectors was probably on foundation don't worry aha

But that is mathematically similar. You are stating that miles = 1.6 kilometres? No, that's contradicting the given example.

Consider this:

You are proposing that miles = 1.6 x kilometres
In this case, 80 kilometres must be 1.6 x 80 = 80 + 48 = 128 miles.
However, 80 kilometres is actually 50 miles.

Rather, consider this:
- y/miles is directly proportional to x/kilometres
- therefore y/x = 50/80 = 5/8 = k
- thus y = 5/8x

Let's check this with the conversion given that 80 km = 50 miles.
50 = 5/8 x 80
50 = 50 --> it works.

Thus, y = 5/8 x = 5x/8.

Reply 268

Original post by bobetter

I did direct proportinal exuation and so got y=x*8/5

might be 5/8 i cant remebr what x and y were

See my earlier comment.

Reply 269

Original post by thekidwhogames

But that is mathematically similar. You are stating that miles = 1.6 kilometres? No, that's contradicting the given example.

Consider this:

You are proposing that miles = 1.6 x kilometres
In this case, 80 kilometres must be 1.6 x 80 = 80 + 48 = 128 miles.
However, 80 kilometres is actually 50 miles.

Rather, consider this:
- y/miles is directly proportional to x/kilometres
- therefore y/x = 50/80 = 5/8 = k
- thus y = 5/8x

Let's check this with the conversion given that 80 km = 50 miles.
50 = 5/8 x 80
50 = 50 --> it works.

Thus, y = 5/8 x = 5x/8.

but 1 miles = 1.6km.

I gave it to google and it gave me around 1.6km.

thus the question said 5 miles : 8 kilometres.

Divide both of the ratious by 5 so u get 1 mile

that gives u 1 miles : 1.6 kilometres.

That is correct.

Reply 270

Original post by rickH123

but 1 miles = 1.6km.

I gave it to google and it gave me around 1.6km.

thus the question said 5 miles : 8 kilometres.

Divide both of the ratious by 5 so u get 1 mile

that gives u 1 miles : 1.6 kilometres.

That is correct.

Exactly...

1 mile = 1.6 km

But your equation, y = 1.6x, implies that 80 kilometres would be y = 1.6 x 80 = 128 miles. You see where I'm going with this?

1 mile = 1.6 km
Therefore mile < kilometre
Therefore y < x
Therefore y = 5/8 x.

Reply 271

Original post by thekidwhogames

Exactly...

1 mile = 1.6 km

But your equation, y = 1.6x, implies that 80 kilometres would be y = 1.6 x 80 = 128 miles. You see where I'm going with this?

1 mile = 1.6 km
Therefore mile < kilometre
Therefore y < x
Therefore y = 5/8 x.

according to you, y = km, and x = miles

according to your equation you state that y = 5/8x

if u put 1 mile into the equation, u get x = 1, which would give u (5x1)/8 = 0.625 km.

But 1 mile =/= 0.625km.

However if u had x = 1 into my equation, u get (8x1)/5 = 1.6 km.

1 mile == 1.6km.

we can put the value of 80 kilometres into miles in to the equation. 80 miles = 128 km.

therefore x = 80

8x80 / 5 = 128. this is correct.

You see the method?

I think u got the x and the y muddled up.

Reply 272

Original post by rickH123

according to you, y = km, and x = miles

according to your equation you state that y = 5/8x

if u put 1 mile into the equation, u get x = 1, which would give u (5x1)/8 = 0.625 km.

But 1 mile =/= 0.625km.

However if u had x = 1 into my equation, u get (8x1)/5 = 1.6 km.

1 mile == 1.6km.

we can put the value of 80 kilometres into miles in to the equation. 80 miles = 128 km.

therefore x = 80

8x80 / 5 = 128. this is correct.

You see the method?

I think u got the x and the y muddled up.

Y was miles. X was kilometres. So you're saying y = 1.6x?
So miles = 1.6 kilometres?
Mate, I'm sure it's miles = 5/8 kilometre.
So y = 5x/8

Can you check it?

What is question 7?

Original post by thekidwhogames

Y was miles. X was kilometres. So you're saying y = 1.6x?
So miles = 1.6 kilometres?
Mate, I'm sure it's miles = 5/8 kilometre.
So y = 5x/8

Can you check it?

y was not miles. The exam paper putted x first, then y. so x = miles, and y was kilometre.

Reply 275

Original post by rickH123

y was not miles. The exam paper putted x first, then y. so x = miles, and y was kilometre.

I'm 100% sure that y was miles, x was kilometres. Even if it wasn't, can you check the equation in this case for y, so miles? Because it was definitely miles as teachers had gotten the answer y = 5x/8.

It wasn't in order hence the confusion.

Reply 276

TheMightyBadger

13

Original post by rickH123

For those wanting to know about the miles to kilometres question. This is how it went

x miles : y kilometres
5 miles : 8 Kilometres

The question states write y in terms of x [2 marks]

step 1, put them in fractions as they are ratio:
This meant; x/y = 5/8
Flip all them over
y/x = 8/5

Now rearrange it, y = (8/5) x = 8x/5

Therefore it WAS y = (8x)/5

In case people don't agree: Here is metric conversions . org's results.

I put in 2 miles, which was around 3.2 kilometres.

2 miles = x miles, therefore x = 2
Put x = 2 into the equation

y = (8x2)/5 = 16/5 = 3.2 kilometres, which is near the value that the website gave me.

If it was (5x)/8 as people are saying, then 2 miles would give me (5x2)8 = 10/8 = 1.25 kilometres, which is incorrect in conversion.

y was miles and x was kilometres...

Reply 277

TheMightyBadger

13

Original post by thekidwhogames

I'm 100% sure that y was miles, x was kilometres. Even if it wasn't, can you check the equation in this case for y, so miles? Because it was definitely miles as teachers had gotten the answer y = 5x/8.

It wasn't in order hence the confusion.

I fully agree with you.

Reply 278

Candy Zhang

7

I forgot about question what is question 7 about!?

Reply 279