Hi, Can you maybe tell us how you got 1637 for the spheres question?
Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube.
Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere)
UB of length of the cube: 4.55cm
LB of the radius of the sphere: 0.25cm (note I converted to cm here)
Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21
Therefore only 1439 spheres can be made from the cube. I know I might be wrong but I cannot find any way of getting 1637 spheres. Could you please post how you got your answer?

Reply 568

username2649513

Original post by mrmaths12345

last question was 188
probability one was 0.298
angles one was 63
cube and sphere one was 1637
all definitely correct

Hi, Can you maybe tell us how you got 1637 for the spheres question?
Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube.
Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere)
UB of length of the cube: 4.55cm
LB of the radius of the sphere: 0.25cm (note I converted to cm here)
Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21 Therefore only 1439 spheres can be made from the cube. I know I might be wrong but I cannot find any way of getting 1637 spheres.
Could you please post how you got your answer?

Reply 569

username2649513

Hi,
Can you maybe tell us how you got 1637 for the spheres question? Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube.
Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere)
UB of length of the cube: 4.55cm
LB of the radius of the sphere: 0.25cm (note I converted to cm here)
Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21
Therefore only 1439 spheres can be made from the cube.
I know I might be wrong but I cannot find any way of getting 1637 spheres. Could you please post how you got your answer?

Reply 570

Martins1

Original post by Niallano

How do you know the answer to Q21 is 25/84? I got 2/7

This is the working:
The only ways to pick out three of the cards and get a total of 6 were to pick out a 1, 2 and 3; or to pick out 2,2 and 2.
The former can be achieved by picking them out in 1 of six orders:
1,2,3
1,3,2
2,3,1
2,1,3
3,1,2
3,2,1
To find out the probability of each of these scenarios, this is how you do it:
(2/9)*(3/8)*(4/7) = 1/21
Since there are 6 of them, multiply 1/21 by 6 = 2/7 (which is what you did)
However you forgot that by picking out three 2's, a total of six could be achieved.
The probability of this is (3/9)*(2/8)*(1/7)=1/84
1/84 + 2/7 = 25/84

Reply 571

username2649513

Original post by mrmaths12345

last question was 188
probability one was 0.298
angles one was 63
cube and sphere one was 1637
all definitely correct

Hi, Can you maybe tell us how you got 1637 for the spheres question? Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube. Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere) UB of length of the cube: 4.55cm LB of the radius of the sphere: 0.25cm (note I converted to cm here) Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21 Therefore only 1439 spheres can be made from the cube. I know I might be wrong but I cannot find any way of getting 1637 spheres. Could you please post how you got your answer?

Reply 572

Tapochek

Guys, if I made the cumulative frequency graph like bar chart, what will I get for the graph itself and the interquartile range question?

Reply 573

WhiteX

Original post by Martins1

hi can i ask you what did you get for the q where you had to find the angle between the AH Line and the plane efgh ? was it 24.1 ?

Reply 574

username2649513

Original post by mrmaths12345

last question was 188
probability one was 0.298
angles one was 63
cube and sphere one was 1637
all definitely correct

Hi, Can you maybe tell us how you got 1637 for the spheres question?
Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube.
Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere)
UB of length of the cube: 4.55cm
LB of the radius of the sphere: 0.25cm (note I converted to cm here)
Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21 Therefore only 1439 spheres can be made from the cube. I know I might be wrong but I cannot find any way of getting 1637 spheres.
Could you please post how you got your answer?

Reply 575

WhiteX

Original post by Tapochek

Guys, if I made the cumulative frequency graph like bar chart, what will I get for the graph itself and the interquartile range question?

the interquartille was 20

Reply 576

WhiteX

Original post by jonitoni2

Hi, Can you maybe tell us how you got 1637 for the spheres question?
Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube.
Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere)
UB of length of the cube: 4.55cm
LB of the radius of the sphere: 0.25cm (note I converted to cm here)
Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21 Therefore only 1439 spheres can be made from the cube. I know I might be wrong but I cannot find any way of getting 1637 spheres.
Could you please post how you got your answer?

hi can i ask you what did you get for the q where you had to find the angle between the AH Line and the plane efgh ? was it 24.1 ?

Reply 577

Tapochek

I have done it the same way and got the same answer, but I think that the upper bound for cube side length was 4.75 instead of 4.55, that's where the answer comes from.

Reply 578

Martins1

Original post by jonitoni2

Hi,
Can you maybe tell us how you got 1637 for the spheres question? Wasn't the question: The cube has a side length of 4.5cm correct to the nearest 0.5cm and the sphere has a radius of 3mm correct to the nearest mm. Calculate the maximum number of spheres that can be made from the cube.
Therefore the answer would be: (Upper bound for the volume of the cube)/(Lower bound of the volume of the sphere)
UB of length of the cube: 4.55cm
LB of the radius of the sphere: 0.25cm (note I converted to cm here)
Answer: (4.55x4.55x4.55)/(4/3xπx0.25^3)= 1439.21
Therefore only 1439 spheres can be made from the cube.
I know I might be wrong but I cannot find any way of getting 1637 spheres. Could you please post how you got your answer?

It said that 4.5 cm was to the nearest 0.5, not 0.1. Therefore the upper bound was 4.75 not 4.55. I did the same. That is only minus two or three marks, dont worry.