
By: drstevewu (offline) Monday, May 13 2013 @ 09:29 PM CDT (Read 1343 times)



drstevewu 
Hi, I wonder if there is another solution to this question:
There were 544 brownies and cupcakes for sale at a bakery. All the brownies at the bakery cost $448 more than all the cupcakes. After 4/5 of the brownies and 1/4 of the cupcakes were sold, there were twice as many brownies as cupcakes left. Each brownie cost $0.80 less than each cupcake. How much did each brownie cost?
Thank you...

Junior
Registered: 04/20/10 Posts: 31





By: echeewh (offline) Tuesday, May 14 2013 @ 12:06 AM CDT



echeewh 
Hi there,
Following pls find my worked solution:
<after>
B 
C 
<process>
B: (4/5) sold
C: (1/4) sold
<Work Backwards>
After (1/4)C was sold, its left with (3/4)C. So, split the 1 part (p) of C into 3. Likewise, the same with the 2 parts (p) of B.
Add 1p of C to its <before> model. Hence, ratio B : C is 6 : 4.
After (4/5)B was sold, its left with (1/5)B. So, split the 6p of B into 30 units (u), where 1p of B = 5u {common multiple of 6 and 5}. Likewise, the same with the 4p of C. giving it 20u.
(1/5)B = 30u
(5/5)B = 5 × 30 = 150u
Hence, ratio B : C is 150 : 20 = 15 : 2
<before>
B : C
15 : 2
Given a total of 544 B and C, we have ...
17u > 544
1u > 32
So ,
B = 15u > 15 × 32 = 480
C = 2u > 2 × 32 = 64
Given that each brownie cost $0.80 less than each cupcake,
1B = 1C  80
Given that all the brownies at the bakery cost $448 more than all the cupcakes, Using <Number x Value> method> , we have ...
480 × (1C  80)  64C = 44800 {where 1C = cost of 1 cupcake}
480C  38400  64C = 44800
416C = 44800 + 38400
416C = 83200
1C = 200 = $2.00
Hence, 1B = 2.00  0.80 = $1.20
========
Trust this helps.
Do let me know again if this is different from your <answerkey> or if theres further clarification.
Cheers,
Edward

Active Member
Registered: 04/21/11 Posts: 627





By: PSRNatarajan (offline) Tuesday, May 14 2013 @ 12:11 AM CDT



PSRNatarajan 
Please see the attachment for the solution

Newbie
Registered: 03/26/12 Posts: 1





By: drstevewu (offline) Tuesday, May 14 2013 @ 10:39 AM CDT



drstevewu 
Hey Edward, thank you very much again for your help..
PSRNatarajan, where can i view/find your attachment?

Junior
Registered: 04/20/10 Posts: 31





By: xiaofenglim (offline) Saturday, August 17 2013 @ 03:42 AM CDT



xiaofenglim 
there are 10 red pens,2 green pens and 4 black pens in a box. what percentage of the pens in the box is black?

Newbie
Registered: 08/05/11 Posts: 1



