Turn on thread page Beta
    • Thread Starter
    Offline

    9
    ReputationRep:
    Steph is solving a problem. Cube A has a surface area of 150 cm2 Cube B has sides half the length of cube A

    What is the volume of cube B?

    To solve this problem, Steph decides to:
    - halve the surface area
    -calculate the square root of the answer then divide by 6
    - then cube this answer to work out the volume.
    Evaluate Steph’s method.

    [2 marks]
    • Community Assistant
    Offline

    17
    ReputationRep:
    Community Assistant
    I won't give the answer but some hints.

    If cube A has surface area 150, then 6x^2=150 --> x^2 = 25. This mean each side length is 5 then you can...?

    Also you probably made a mistake copying the question in the second bullet point -these shouldn't be together in the same point.
    • Thread Starter
    Offline

    9
    ReputationRep:
    (Original post by thekidwhogames)
    I won't give the answer but some hints.

    If cube A has surface area 150, then 6x^2=150 --> x^2 = 25. This mean each side length is 5 then you can...?

    Also you probably made a mistake copying the question in the second bullet point -these shouldn't be together in the same point.
    I actually have no idea whats going on and its 2 marks as well- don't understand.
    Offline

    18
    ReputationRep:
    (Original post by GCSE_18)
    Steph is solving a problem. Cube A has a surface area of 150 cm2 Cube B has sides half the length of cube A

    What is the volume of cube B?

    To solve this problem, Steph decides to:
    - halve the surface area
    -calculate the square root of the answer then divide by 6
    - then cube this answer to work out the volume.
    Evaluate Steph’s method.

    [2 marks]
    First, ignore Steph and work it out yourself. Then point out the differences in your method and Steph's method and say why his answer is the same or is different to your answer
    Offline

    18
    ReputationRep:
    (Original post by GCSE_18)
    Steph is solving a problem. Cube A has a surface area of 150 cm2 Cube B has sides half the length of cube A

    What is the volume of cube B?

    To solve this problem, Steph decides to:
    - halve the surface area
    -calculate the square root of the answer then divide by 6
    - then cube this answer to work out the volume.
    Evaluate Steph’s method.

    [2 marks]
    You know a cube has 6 sides, so do 150 divided by 6 and you have the area of 1 side. you should be able to do it from there
    • Thread Starter
    Offline

    9
    ReputationRep:
    (Original post by Baza2002)
    You know a cube has 6 sides, so do 150 divided by 6 and you have the area of 1 side. you should be able to do it from there
    Thank You, however, I need help on how to do Steph's method without a calculator (i looked at the mark scheme but find it hard to understand it).
    • TSR Support Team
    Online

    21
    ReputationRep:
    TSR Support Team
    (Original post by GCSE_18)
    Steph is solving a problem. Cube A has a surface area of 150 cm2 Cube B has sides half the length of cube A

    What is the volume of cube B?

    To solve this problem, Steph decides to:
    - halve the surface area
    -calculate the square root of the answer then divide by 6
    - then cube this answer to work out the volume.
    Evaluate Steph’s method.

    [2 marks]
    Hi there :wavey:
    I've moved your thread to the Maths forum where hopefully you'll get more answers In future, it's best to select the subject from the list here and create a thread in there instead :yep: If you want to see where threads belong, check out this thread
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: March 3, 2018

University open days

  1. University of Bradford
    University-wide Postgraduate
    Wed, 25 Jul '18
  2. University of Buckingham
    Psychology Taster Tutorial Undergraduate
    Wed, 25 Jul '18
  3. Bournemouth University
    Clearing Campus Visit Undergraduate
    Wed, 1 Aug '18
Poll
How are you feeling in the run-up to Results Day 2018?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.