Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    Hi

    What do I do when met with a typical question such as

    Mr Harris had a party, he bought some bottles of lemonade costing 75p each and some bottles of orange juice costing 82p each. Altogether he spent £71.94. How many bottles of orange juice did he buy?

    I know the trial and error method, but I hate, hate, hate that method with a passion, so I was wondering if I can do it another way, say, using algebra?

    thanks!
    Offline

    13
    ReputationRep:
    Substitution
    Let qty orange = g
    Let qty lemon.. = n

    We know g+n= 75+82 = 157
    and
    75n + 82g = 7194

    So if g+n = 157 then n = 157-g

    Substitute n into bigger eq,

    75(157-g) + 82g = 7194

    Then solve for g with algebraic manipulation.
    Then substitute g again into 75n + 82g = 7194 to get n.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What's your favourite Christmas sweets?
    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
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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

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