Welcome! Check out our free B-School Guides to learn how you compare with other applicants.

## 500 ps test 22 test#15

This topic has 6 member replies
dunkin77 Really wants to Beat The GMAT!
Joined
01 Apr 2007
Posted:
269 messages
500 ps test 22 test#15 Sun Apr 15, 2007 11:27 am
Elapsed Time: 00:00
• Lap #[LAPCOUNT] ([LAPTIME])
Hi,

I could not find an answer for this question but I think the answer is B) -- Can anyone please tell me B) is correct?

15. A certain used-book dealer sells paperback books at 3 times dealer's cost and hardback books at 4 times dealer's cost. Last week the dealer sold a total of 120 books, each of which had cost the dealer \$1. If the gross profit (sales revenue minus dealer's cost) on the sale of all of these books was \$300, how many of the books sold were paperbacks?
(A) 40
(B) 60
(C) 75
(D) 90
(E) 100

Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
jayhawk2001 Community Manager
Joined
28 Jan 2007
Posted:
789 messages
Followed by:
1 members
Thanked:
25 times
Sun Apr 15, 2007 1:10 pm
3p + 4(120-p) = 120 + 300
p = 60

dunkin77 Really wants to Beat The GMAT!
Joined
01 Apr 2007
Posted:
269 messages
Sun Apr 15, 2007 2:28 pm
Thank you Jay for your response.

What I thought I did was...

3P + 4H = 300
P + H = 120

3P+4(120-p)=300
p=180???

I thought I got B) but now I can't remember how I got p=60.

Can you explain how come you add 120 to 300 ?

ns88 Rising GMAT Star
Joined
14 Apr 2007
Posted:
33 messages
Sun Apr 15, 2007 3:15 pm
paperback=x
hardcover=y

total books= 120=x+y

total cost \$120= 3x+4y

total revenue= (3)(\$1)x+ 4(\$1)y= 3x+4y

profit= 300 = (3x+4y)- 120

or 420=3x +4y

since 120= x+ y

x=(120-y)

420= [(3)(120-y) +4y]

y=60

x=60

jayhawk2001 Community Manager
Joined
28 Jan 2007
Posted:
789 messages
Followed by:
1 members
Thanked:
25 times
Sun Apr 15, 2007 3:33 pm
dunkin77 wrote:
Thank you Jay for your response.

What I thought I did was...

3P + 4H = 300
P + H = 120

3P+4(120-p)=300
p=180???

I thought I got B) but now I can't remember how I got p=60.

Can you explain how come you add 120 to 300 ?

The question states that the difference between the revenus
and the cost is 300. The cost is 120 * \$1 = 120. Hence 120 + 300
is the total sale price.

dunkin77 Really wants to Beat The GMAT!
Joined
01 Apr 2007
Posted:
269 messages
Sun Apr 15, 2007 7:16 pm
Okay - thanks!!

now I remember what I did...

3p+4H - (p+H) = 300

P+H = 120

but yours is more efficient way!!

Thank you!

Cybermusings GMAT Destroyer!
Joined
27 Mar 2007
Posted:
559 messages
Followed by:
1 members
Thanked:
4 times
Mon Apr 16, 2007 5:31 am
Suppose the dealer sold x paperback books and y hardback books.
x+y = 120 ---------- 1)
3x+4y-120 = 300 ------- 2)
Solving the 2 you'll get x = 60 books

### Best Conversation Starters

1 vipulgoyal 32 topics
2 hemant_rajput 23 topics
3 guerrero 18 topics
4 abhirup1711 17 topics
5 sana.noor 16 topics
See More Top Beat The GMAT Members...

### Most Active Experts

1 Brent@GMATPrepNow

GMAT Prep Now Teacher

211 posts
2 GMATGuruNY

The Princeton Review Teacher

137 posts
3 Jim@StratusPrep

Stratus Prep

60 posts