Chris mixed 3 pounds of raisins with 4 pounds of nuts. If a pound of nuts costs 3 times as much as a pound of raisins, then the total cost of the raisins was what fraction of the total cost of the mixture?
A.3/7
B.1/3
C.1/4
D.1/5
E.1/7
Problem solving
This topic has expert replies
GMAT/MBA Expert
- Brent@GMATPrepNow
- GMAT Instructor
- Posts: 16207
- Joined: Mon Dec 08, 2008 6:26 pm
- Location: Vancouver, BC
- Thanked: 5254 times
- Followed by:1268 members
- GMAT Score:770
A fast approach is to choose some nice values for the per-pound costs.Newaz111 wrote:Chris mixed 3 pounds of raisins with 4 pounds of nuts. If a pound of nuts costs 3 times as much as a pound of raisins, then the total cost of the raisins was what fraction of the total cost of the mixture?
A.3/7
B.1/3
C.1/4
D.1/5
E.1/7
Let the raisins cost $1 PER POUND
This mean the nuts cost $3 PER POUND [since a pound of nuts costs 3 times as much as a pound of raisins]
3 pounds of raisins costs (3 pounds)($1/pound) = $3
4 pounds of nuts costs (4 pounds)($3/pound) = $12
TOTAL COST = $3 + $12 = $15
The total cost of the raisins was what fraction of the total cost of the mixture?
$3/$15 = [spoiler]1/5 = D[/spoiler]
Cheers,
Brent
GMAT/MBA Expert
- [email protected]
- Elite Legendary Member
- Posts: 10392
- Joined: Sun Jun 23, 2013 6:38 pm
- Location: Palo Alto, CA
- Thanked: 2867 times
- Followed by:511 members
- GMAT Score:800
Hi Newaz111,
TESTing VALUES (the approach that Brent used) is a great approach for these types of questions. You can also solve this question with Algebra...
We have 3 pounds of raisins and 4 pounds of nuts. We're told that a pound of nuts costs 3 TIMES as much as a pound of raisins, so we can call the prices:
X = price per pound of raisins
3X = price per pound of nuts
The total price of this mixture would then be:
3(X) + 4(3X) = 3X + 12X = 15X
We're asked for the total cost of the raisins divided by the total cost of the mixture:
Total cost of raisins: 3X
Total cost of he mix: 15X
3X/15X = 1/5
Final Answer: D
GMAT assassins aren't born, they're made,
Rich
TESTing VALUES (the approach that Brent used) is a great approach for these types of questions. You can also solve this question with Algebra...
We have 3 pounds of raisins and 4 pounds of nuts. We're told that a pound of nuts costs 3 TIMES as much as a pound of raisins, so we can call the prices:
X = price per pound of raisins
3X = price per pound of nuts
The total price of this mixture would then be:
3(X) + 4(3X) = 3X + 12X = 15X
We're asked for the total cost of the raisins divided by the total cost of the mixture:
Total cost of raisins: 3X
Total cost of he mix: 15X
3X/15X = 1/5
Final Answer: D
GMAT assassins aren't born, they're made,
Rich