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1. 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

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.
2. (0.8*y)*1.05=71.40

rest is down to you.
3. (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
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]
4. 71.4/1.05=ANS
ANS/0.8=y
5. =85
6. (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
https://www.thestudentroom.co.uk/sho....php?t=4919248
7. Thank you everyone, I get it now!

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