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    The price of an item, y, is discounted by 20%.
    5% of the discounted price is added on for sales tax.
    The final price including sales tax is $71.40. What is the original price y?
    a) $59.50
    b) $81.40
    c) $84.00
    d) $85.00
    e) $86.40
    Which one is the answer? Please show working out

    I did the working out but my answer isn't in one of the options
    I did 0.8*y + (0.2*0.05*y) = 0.8y +0.01y = 71.40
    0.81y = 71.40
    therfore y = 88.15

    Using my y value I calculated the 20% disocunt and added the 5% discounted value and and I do get $71.40. I don't know where I'm going wrong.
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    (0.8*y)*1.05=71.40

    rest is down to you.
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    (Original post by mary_hale267)
    The price of an item, y, is discounted by 20%.
    5% of the discounted price is added on for sales tax.
    The final price including sales tax is $71.40. What is the original price y?
    a) $59.50
    b) $81.40
    c) $84.00
    d) $85.00
    e) $86.40
    Which one is the answer? Please show working out
    Go backwards.To find percentags its times to find the discount, so the inverse would be divide. Hopefully you'll know where to go now.
    ex. To find 20% of £45 would be 45 x (20/100) = 45 x 0.2 = £9, whereas the inverse would be £9 / (20/100) = £9 / 0.2 = £45 [Latex isn't working]
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    71.4/1.05=ANS
    ANS/0.8=y
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    =85
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    (Original post by wiseguy99)
    (0.8*y)*1.05=71.40

    rest is down to you.
    (Original post by N/A IS THE NAME)
    Answer should be $85 i think
    (Original post by N/A IS THE NAME)
    =85
    Read the guidance...
    https://www.thestudentroom.co.uk/sho....php?t=4919248
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    Thank you everyone, I get it now!
 
 
 
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