Maths year 11

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    Just add the short explanation that you did the operation 4 times, so the shop closes at the end of the fifth month, aka the end of May. But yes, correct!


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    An algebraic method:

    50000\times(0.9^n) = 35000

    0.9^n = 0.7

    n = \log_{0.9} 0.7 = 3.385...

    The smallest whole number greater than 3.385... is 4, therefore the multiplier must be applied 4 times, hence the price went below £35000 on the fifth month, May.

    Don't worry about this, it is much more advanced than you need for GCSE.
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    (Original post by K-Man_PhysCheM)
    Just add the short explanation that you did the operation 4 times, so the shop closes at the end of the fifth month, aka the end of May. But yes, correct!


    Spoiler:
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    An algebraic method:

    50000\times(0.9^n) = 35000

    0.9^n = 0.7

    n = \log_{0.9} 0.7 = 3.385...

    The smallest whole number greater than 3.385... is 4, therefore the multiplier must be applied 4 times, hence the price went below £35000 on the fifth month, May.

    Don't worry about this, it is much more advanced than you need for GCSE.
    Thank youuu

    Can you do an example on a simple percentage increase ans decrease

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    (Original post by z_o_e)
    Thank youuu

    Can you do an example on a simple percentage increase ans decrease

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    1. Dodgy Dan buys cars and sells them at 25% more. He buys a Prius at £26000. How much does he sell it for?

    2. A carpet store sells a carpet for £20 per square meter. For their summer sale, they reduce all their prices by 20%.

    (a) What is the cost per square meter of carpet during the sale?

    (b) Natalie wants to buy 12 square meters of carpet. How much will she save by buying during the sale instead of buying at the normal price?

    3. A car costs £20000 in January. Its price decreases by 15% each month. What is its cost in April?

    4. A sale decreases all prices by 20%. During the sale, a coat costs £72. What was its original price, before the sale?

    5*. James earns 80% compared to what his wife Rachel earns (for every £100 she earns, James earns only £80, and together combined they earn £180). If they both combined earn £20250 per year, how much does James earn per year?
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    (Original post by K-Man_PhysCheM)
    1. Dodgy Dan buys cars and sells them at 25% more. He buys a Prius at £26000. How much does he sell it for?

    2. A carpet store sells a carpet for £20 per square meter. For their summer sale, they reduce all their prices by 20%.

    (a) What is the cost per square meter of carpet during the sale?

    (b) Natalie wants to buy 12 square meters of carpet. How much will she save by buying during the sale instead of buying at the normal price?

    3. A car costs £20000 in January. Its price decreases by 15% each month. What is its cost in April?

    4. A sale decreases all prices by 20%. During the sale, a coat costs £72. What was its original price, before the sale?

    5*. James earns 80% compared to what his wife Rachel earns (for every £100 she earns, James earns only £80, and together combined they earn £180). If they both combined earn £20250 per year, how much does James earn per year?
    So I do 100-25

    Times that by the originals ans?

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    (Original post by z_o_e)
    So I do 100-25

    Times that by the originals ans?

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    For the first question, he sells them for 25% more, so there is a 25% increase in price.

    100% + 25% = 125%

    The multiplier is \dfrac{percentage}{100}.

    In this case, that is \frac{125}{100}, or 1.25
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    (Original post by K-Man_PhysCheM)
    For the first question, he sells them for 25% more, so there is a 25% increase in price.

    100% + 25% = 125%

    The multiplier is \dfrac{percentage}{100}.

    In this case, that is \frac{125}{100}, or 1.25


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    1 is correct.

    2(a) is correct. 2(b) asks for how much was saved, so you need the difference between the normal price for 12m^2 and the sale price. You've already calculated these two. You would have gained 2/3 marks for part (b).

    3 is correct.

    4 is not correct. During the sale, it costs £72. Also during the sale, all prices have been reduced by 20%.
    This means that £72 is 80% of the jacket's normal price. The normal price has been reduced by 20% to give a sale price of £72. Or:

    Normal price x multiplier = £72

    Hence, normal price = £72/multiplier.

    Find the multiplier for the 20% reduction, then find the normal price.
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    (Original post by z_o_e)
    Heya, my end of year exam is coming up and I'm doing higher and I'm getting D's I'm currently in year 10 and I know I can do better if I revise. Is anyone else willing to help me with a few questions ?


    In year 11 now.
    Grade achieved end of year : C
    I would but I got a f in maths sorry
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    (Original post by K-Man_PhysCheM)
    1 is correct.

    2(a) is correct. 2(b) asks for how much was saved, so you need the difference between the normal price for 12m^2 and the sale price. You've already calculated these two. You would have gained 2/3 marks for part (b).

    3 is correct.

    4 is not correct. During the sale, it costs £72. Also during the sale, all prices have been reduced by 20%.
    This means that £72 is 80% of the jacket's normal price. The normal price has been reduced by 20% to give a sale price of £72. Or:

    Normal price x multiplier = £72

    Hence, normal price = £72/multiplier.

    Find the multiplier for the 20% reduction, then find the normal price.
    Thank youuu

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    (Original post by K-Man_PhysCheM)
    1 is correct.

    2(a) is correct. 2(b) asks for how much was saved, so you need the difference between the normal price for 12m^2 and the sale price. You've already calculated these two. You would have gained 2/3 marks for part (b).

    3 is correct.

    4 is not correct. During the sale, it costs £72. Also during the sale, all prices have been reduced by 20%.
    This means that £72 is 80% of the jacket's normal price. The normal price has been reduced by 20% to give a sale price of £72. Or:

    Normal price x multiplier = £72

    Hence, normal price = £72/multiplier.

    Find the multiplier for the 20% reduction, then find the normal price.
    I don't get 4 tho

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    (Original post by z_o_e)
    I don't get 4 tho

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    You have an item which costs, lets say, £P before the sale. The sale is 20%, and the item decreases to the price of £72.

    A full price is 100%, so a 20% decrease would bring it down to 80%. 80% as a decimal is 0.8.

    So we know that 80% of P is equal to 72.

    Simply construct an equation to solve for P: P \cdot 0.8 = 72
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    (Original post by RDKGames)
    You have an item which costs, lets say, £P before the sale. The sale is 20%, and the item decreases to the price of £72.

    A full price is 100%, so a 20% decrease would bring it down to 80%. 80% as a decimal is 0.8.

    So we know that 80% of P is equal to 72.

    Simply construct an equation to solve for P: P \cdot 0.8 = 72
    How do I do these...

    No answers please


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    (Original post by z_o_e)
    How do I do these...

    No answers please


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    You got the first one right, and the second one is essentially the same idea but you have 2 variables.

    What is the expression for p boxes of 10 pencils? What is the expression for r boxes of 12 pencils? What is the total amount of pencils in terms of p and r?
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    (Original post by RDKGames)
    You got the first one right, and the second one is essentially the same idea but you have 2 variables.

    What is the expression for p boxes of 10 pencils? What is the expression for r boxes of 12 pencils? What is the total amount of pencils in terms of p and r?
    P+R


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    (Original post by RDKGames)
    You got the first one right, and the second one is essentially the same idea but you have 2 variables.

    What is the expression for p boxes of 10 pencils? What is the expression for r boxes of 12 pencils? What is the total amount of pencils in terms of p and r?
    Also Is this correct



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    Nope. If I buy 2 boxes of 10 pencils, and 1 box of 12 pencils, will I really have only 3 pencils in total???

    (Original post by z_o_e)
    Also Is this correct



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    First one is fine, but the second one doesn't follow the pattern because (-29)+(-8)\not=13

    Better start off by saying c+34=55 and c will be your 3rd box.

    Then say b+c=34 where b is your second box.

    And finally the last box would satisfy a+b=c where a is your first box.
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    (Original post by z_o_e)
    Heya, my end of year exam is coming up and I'm doing higher and I'm getting D's I'm currently in year 10 and I know I can do better if I revise. Is anyone else willing to help me with a few questions ?


    In year 11 now.
    Grade achieved end of year : C
    I cannot STRESS this enough... but PAST PAPERS are SO SO important for maths! Do EVERY SINGLE ONE! (even the old spec for you guys). What grade do you want to achieve in your final exam?
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    (Original post by sunshine774)
    I cannot STRESS this enough... but PAST PAPERS are SO SO important for maths! Do EVERY SINGLE ONE! (even the old spec for you guys). What grade do you want to achieve in your final exam?
    Level 6 or 7

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    (Original post by z_o_e)
    Level 6 or 7

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    So is that grade A or grade B? I did the old spec last year so not sure...
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    (Original post by sunshine774)
    So is that grade A or grade B? I did the old spec last year so not sure...
    High B.

    What grade did you get?

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