Maths Question
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Maths Question
Hello everyone.
Please what is the quickest and easiest way of working this question out?
The local bookshop has a sale. Every item in the shop is reduced by 25%.
Melanie bought a picture for £1.50
What was the price of the picture book BEFORE the sale started?
Please what is the quickest and easiest way of working this question out?
The local bookshop has a sale. Every item in the shop is reduced by 25%.
Melanie bought a picture for £1.50
What was the price of the picture book BEFORE the sale started?
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- Posts: 41
- Joined: Wed Jul 11, 2007 10:53 pm
I taught dd one way to do nearly all these kind of percentage and fraction questions as she was getting confused-
part percentage
------ x -------------
whole 100
put in the numbers you have, then multiply by the diagonal number and divide by the other number.
1.50( part of the whole number) 75( you know 1.50 is 75% of the whole)
----- x ----
? 100
1.50x100 / 75 = 2.00
I hope I've put that in right, gotta dash up to school now.
part percentage
------ x -------------
whole 100
put in the numbers you have, then multiply by the diagonal number and divide by the other number.
1.50( part of the whole number) 75( you know 1.50 is 75% of the whole)
----- x ----
? 100
1.50x100 / 75 = 2.00
I hope I've put that in right, gotta dash up to school now.
If you are asked to find an original price, put 100 over the percentage you have (75, in the above example), cancel this improper fraction down to its lowest terms, and multiply the resulting 'constant fraction' by any discounted price, cross-cancelling if possible, to find the original cost.
Taking the above example:
100/75 x 150/1 = 4/3 x 150/1 = 4/1 x 50/1 = 200 = £2 (This obviously would benefit from standard fraction formatting!)
If you have the original price and need to find out what the discounted price would be, you just need to invert the 'constant fraction'.
E.g. 3/4 x 200/1 = 3/1 x 50/1 = 150 = £1.50
Taking the above example:
100/75 x 150/1 = 4/3 x 150/1 = 4/1 x 50/1 = 200 = £2 (This obviously would benefit from standard fraction formatting!)
If you have the original price and need to find out what the discounted price would be, you just need to invert the 'constant fraction'.
E.g. 3/4 x 200/1 = 3/1 x 50/1 = 150 = £1.50