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Pre Maths Paper 1 Help

  • 18-02-2013 9:34pm
    #1
    Banned (with Prison Access) Posts: 759 ✭✭✭


    Could anyone help and take their time out to tell me how to do Q.2 (c)
    Thank you, much appreciated

    <image of copyrighted file removed>


Comments

  • Registered Users, Registered Users 2 Posts: 191 ✭✭Bluestrike


    Could anyone help and take their time out to tell me how to do Q.2 (c)
    Thank you, much appreciated

    I had that for Christmas and i got full marks so here, it won't be very good quality as its my phone but hopefully u can see it


  • Registered Users, Registered Users 2 Posts: 191 ✭✭Bluestrike


    Bluestrike wrote: »

    I had that for Christmas and i got full marks so here, it won't be very good quality as its my phone but hopefully u can see it

    Sorry, my phone won't upload it for some reason
    just put in stuff u know for sure (stuff that says only). To get A etc you have to add up the centre and the parts where that circle and another collide and take that away from amount in A

    Eg: 36 in A, 7 in A and B, x in A and C, 10 in A and B and C

    you would do 36-(7+x+10)
    36-(10+x)
    36-10-x
    24-x

    Then put that figure in A and do same for rest
    to find x u put the total on one side and add up all the figures in the different sections. You should get the total on the left and i higher sum minus x on other. Simply use algebra to find answer then


  • Banned (with Prison Access) Posts: 759 ✭✭✭Man City 10


    Bluestrike wrote: »
    Sorry, my phone won't upload it for some reason
    just put in stuff u know for sure (stuff that says only). To get A etc you have to add up the centre and the parts where that circle and another collide and take that away from amount in A

    Eg: 36 in A, 7 in A and B, x in A and C, 10 in A and B and C

    you would do 36-(7+x+10)
    36-(10+x)
    36-10-x
    24-x

    Then put that figure in A and do same for rest
    to find x u put the total on one side and add up all the figures in the different sections. You should get the total on the left and i higher sum minus x on other. Simply use algebra to find answer then

    any chance you can tell me the answer because how did you get 36 if there is only 31 in a


  • Registered Users, Registered Users 2 Posts: 191 ✭✭Bluestrike


    any chance you can tell me the answer because how did you get 36 if there is only 31 in a

    I was just using that as an example but the answers are
    (i) A is 12
    A union C (AUC) is 10
    A union B (AUB) is 4
    B union C (BUC) is x
    A union B union C (AUBUC) is 5
    B is 12-x (21-(4+5+x) = 21-9-x = 12-x)
    C is 7-x (22-(10+5+x) = 22-15-x = 7-x)

    (ii) The maximum it can be is 7 as C is 7-x so if x was 8 it would be 7-8 and you cant have a minus number of people

    (iii) I'm not fully sure with this one but i think it is 7 again because the C thing with 7-x?????

    (iv) 48 = 12+4+5+10+x+12-x+7-x
    48 = 50-x
    x+48 = 50
    x = 50-48
    x = 2

    I think thats it, if you have any other querries i would be happy to help :cool:


  • Banned (with Prison Access) Posts: 759 ✭✭✭Man City 10


    Bluestrike wrote: »
    I was just using that as an example but the answers are
    (i) A is 12
    A union C (AUC) is 10
    A union B (AUB) is 4
    B union C (BUC) is x
    A union B union C (AUBUC) is 5
    B is 12-x (21-(4+5+x) = 21-9-x = 12-x)
    C is 7-x (22-(10+5+x) = 22-15-x = 7-x)

    (ii) The maximum it can be is 7 as C is 7-x so if x was 8 it would be 7-8 and you cant have a minus number of people

    (iii) I'm not fully sure with this one but i think it is 7 again because the C thing with 7-x?????

    (iv) 48 = 12+4+5+10+x+12-x+7-x
    48 = 50-x
    x+48 = 50
    x = 50-48
    x = 2

    I think thats it, if you have any other querries i would be happy to help :cool:

    Thanks


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  • Registered Users, Registered Users 2 Posts: 36 bosco9871


    Can anyone show me how to do this Quadratic equation please.

    Solve the equation x²-2x-8=0
    Hence solve the equation (y-3)² -2 (y-3) -8 =0

    Thank you.


  • Closed Accounts Posts: 890 ✭✭✭dh0011


    solns to quadratic are 4 and -2
    soln to second equation is got by letting y-3 equal to the solutions in the first eqn giving 7 and 1.


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