BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

faster way to do bth questions??/

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Senior | Next Rank: 100 Posts
Posts: 71
Joined: Sun May 18, 2008 11:04 pm
Thanked: 1 times

faster way to do bth questions??/

by charmaine » Mon Oct 20, 2008 10:15 pm
14. A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 6 percent and 8 percent, respectively. If the total interest on the two certificates was $1,440 at the end of one year, what fractional part of the $20.000 was invested at the higher rate?
(A)
(B)
(C)
(D)
(E)


17. Kim bought a total of $2.65 worth of postage stamps in four denominations. If she bought an equal number of 5-cent and 25-cent stamps and twice as many 10-cent stamps as 5-cent stamps, what is the least number of 1-cent stamps she could have bought ?
(A) 5
(B) 10
(C) 15
(D) 20
(E) 25

....14.D....17.C
Top
Source: — Problem Solving |
Legendary Member
Posts: 829
Joined: Mon Jul 07, 2008 10:09 pm
Location: INDIA
Thanked: 84 times
Followed by:3 members

Re: faster way to do bth questions??/

by sudhir3127 » Mon Oct 20, 2008 10:34 pm
charmaine wrote:14. A total of $20,000 was invested in two certificates of deposit at simple annual interest rates of 6 percent and 8 percent, respectively. If the total interest on the two certificates was $1,440 at the end of one year, what fractional part of the $20.000 was invested at the higher rate?
(A)
(B)
(C)
(D)
(E)


17. Kim bought a total of $2.65 worth of postage stamps in four denominations. If she bought an equal number of 5-cent and 25-cent stamps and twice as many 10-cent stamps as 5-cent stamps, what is the least number of 1-cent stamps she could have bought ?
(A) 5
(B) 10
(C) 15
(D) 20
(E) 25

....14.D....17.C
Please post 1 question per thread...

17.

Equation from the given conditions
5x+ 25x + 2x(10) + y = 265

that is 50x + y = 265

Rule : "When you are asked to minimize a quantity,you must maximize all others and vice-versa"

that the max value of X can be 5 .

thus its
50*5 + y= 265
hence y = 15

hope that helps..
Top
Senior | Next Rank: 100 Posts
Posts: 71
Joined: Sun May 18, 2008 11:04 pm
Thanked: 1 times

by charmaine » Tue Oct 21, 2008 12:21 am
ans. is 3/5
sorry my mistake :(

and thank you sudhir3127...i got it :)
really appreciate it :)
Top
Senior | Next Rank: 100 Posts
Posts: 46
Joined: Mon Jul 07, 2008 12:10 pm
Location: Atlanta
Thanked: 5 times
Followed by:1 members

by lachlanc » Tue Oct 21, 2008 5:57 am
Solution to first question -

let x = $ amount invested at the higher rate

0.08x + 0.06(20,000 - x) = 1440

0.08x + 1200 - 0.06x = 1440

0.02x = 240

x = 12,000

12,000 / 20,000 = 3/5
Top
Post new topic Post Reply
• Page 1 of 1