Turn on thread page Beta
    Offline

    0
    ReputationRep:
    (Original post by samdavyson)
    I did Edexcel Modular but I think that they used some of the same questions.

    We had the probability at the end with 2n² - 35n + 98 = 0. The question originated around balls in a bag with 7 white and n yellow.

    I think that I got them all out in the end. I will post my solution if anyone wants me to.
    yer please.
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Yeah, it's so grrrr though. I did loads of work for geography, found it impossible, none for biology and found it easy It's stupid! How many exams have you got left now?
    6 modules left, economics on monday - i need to learn alot over the weekend... :eek:
    Offline

    2
    ReputationRep:
    (Original post by TheWolf)
    6 modules left, economics on monday - i need to learn alot over the weekend... :eek:
    Mmm! I'm bricking it about the economics, I really want a high A in that, so much pressure, and the time's always so tight! You on edexcel?
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Mmm! I'm bricking it about the economics, I really want a high A in that, so much pressure, and the time's always so tight! You on edexcel?
    nope aqa, i find micro easy, macro - i still dont understand a few things, + i need to do an environment/housing paper, so yea 3 hours of economics nonstop :eek:
    • Thread Starter
    Offline

    0
    ReputationRep:
    thats good, but i didnt think 7/(n+7) was in terms of n...?
    i didnt no what to do after that one!i got 8 more to go now, but all the hard ones..chem, maths 2, physics, eng1+2 french writing.got any tips for any of them??im really down after this 1!
    Offline

    2
    ReputationRep:
    (Original post by TheWolf)
    nope aqa, i find micro easy, macro - i still dont understand a few things, + i need to do an environment/housing paper, so yea 3 hours of economics nonstop :eek:
    Yeah unit 3 is the only one I'm dreading really. 3 hours non-stp for me too, my bum went numb in bio today! It was so hot too, and this owl was hooting outside the window.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by andy_)
    yer please.
    pls could i have it...was woth 13 marks which is why i forced myself to write something down!
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Yeah unit 3 is the only one I'm dreading really. 3 hours non-stp for me too, my bum went numb in bio today! It was so hot too, and this owl was hooting outside the window.
    We had pidgeons flying inside the hall during biology today! And they were 'cooing'. It was very distracting!
    Offline

    0
    ReputationRep:
    That exam was really hard, but also because my teacher is crap and he hadn't taught us most of it...

    Some people were actually crying DURING the exam (and after too!), I only felt like crying though...
    Offline

    2
    ReputationRep:
    (Original post by Ramaya)
    We had pidgeons flying inside the hall during biology today! And they were 'cooing'. It was very distracting!
    Lol, there's always something that distracts you!
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Lol, there's always something that distracts you!
    yes my mate infront of me was farting :mad:
    Offline

    2
    ReputationRep:
    (Original post by TheWolf)
    yes my mate infront of me was farting :mad:
    Lol nice. I had a girl that wheezes behind me in geography, and a girl who kept cracking her knuckles next to me!
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Lol nice. I had a girl that wheezes behind me in geography, and a girl who kept cracking her knuckles next to me!
    hehe for economics im gonna bring loadsa food + drinks in - i was soo hungry after 2 hours of geog
    Offline

    2
    ReputationRep:
    (Original post by TheWolf)
    hehe for economics im gonna bring loadsa food + drinks in - i was soo hungry after 2 hours of geog
    How cam you get that hungry after 2 hours?! Silly boy! We're not allowed food or drink, I was thirsty in bio, and I needed a wee!
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    How cam you get that hungry after 2 hours?! Silly boy! We're not allowed food or drink, I was thirsty in bio, and I needed a wee!
    no food or drink! that sucks 100%, we can bring food + drinks. it was so hot i drunk 2 litres of water which wasnt a great idea. anyways i should stop hijankin this thread soz guys +ladies
    Offline

    2
    ReputationRep:
    (Original post by TheWolf)
    no food or drink! that sucks 100%, we can bring food + drinks. it was so hot i drunk 2 litres of water which wasnt a great idea. anyways i should stop hijankin this thread soz guys +ladies
    Heh, yeah you naughty boy!
    So yeah... that GCSE maths paper today, hard stuff....
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Heh, yeah you naughty boy!
    So yeah... that GCSE maths paper today, hard stuff....
    so whats the weather like in london
    Offline

    2
    ReputationRep:
    (Original post by TheWolf)
    so whats the weather like in london
    Hehe, it's hot with a capital H!!!
    My hot tub warmed itself in the heat!
    Offline

    2
    ReputationRep:
    (Original post by Ellie4)
    Hehe, it's hot with a capital H!!!
    My hot tub warmed itself in the heat!
    yea it was worse during the exams tho! we had to wear our school uniforms too which was 101.3% gay :eek: anyways better do some revision cya!
    Offline

    2
    ReputationRep:
    (Original post by andy_)
    yer please.
    Ok. First part: Factorise 2n² - 35n + 98 = 0.

    (2n - 7) (n - 14)

    Second Part: Solve 2n² - 35n + 98 = 0.

    n = 7/2 = 3.5

    or: n = 14

    Third Part: There are n white balls and 7 yellow in a bag. What is the probability of getting a yellow ball?

    7/(n+7)

    Forth Part: Bill thinks that it is 2/5. Why is he wrong?

    As 7 = 2 (3.5), (n+7) would have to equal 5 (3.5). This creates a non-whole number of balls in the bag.

    (I got that one wrong, but the above is the answer).

    Fifth Part: The probability of Mary and John getting different coloured balls (when they replace them immediately after picking) is 4/9. Show that this can be written as 2n² - 35n + 98 = 0.

    [ (7/(n+7)) x (n/(n+7)) ] + [ (n/(n+7)) x (7/(n+7)) ] = 4/9

    7n / (n+7)² + 7n / (n+7)² = 4/9

    14n / (n+7)² = 4/9

    14n = [ 4(n+7)² ]/9

    9 (14n) = [ 4(n+7)² ]

    126n = 4(n² + 14n + 49)

    126n = 4n² + 56n + 196

    4n² - 70n + 196 = 0

    Therefore:

    2n² - 35n + 98 = 0

    Part Six: Find the probability of Mary and John both getting Yellow Balls.

    [7/(n+7)] x [7/(n+7)] = 49 / (n+7)²

    = 49 / (n² + 14n + 49)

    n = 14 as n is a whole number of balls so it cannot be 3.5.

    Therefore:

    49 / 14² + 14(14) + 49

    49 / 196 + 196 + 49

    49/441 = 1/9

    Any errors?
 
 
 

3,139

students online now

800,000+

Exam discussions

Find your exam discussion here

Poll
Should predicted grades be removed from the uni application process

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.