Hi All,
In these types of DS questions, if you're sure if a pattern exists or not, you can prove it by TESTing VALUES and being thorough. Here's how:
We're told that Pat bought 5 pounds of apples. We're asked how many pounds of pears could have been purchased with the same amount of money.
**Note: I'm going to assume that both the cost per pound of apples and the cost per pound of pears remains constant.**
Fact 1: 1 pound of pears costs $0.5 more than 1 pound of apples.
IF....
A pound of apples cost $1, then a pound of pears costs $1.50
5 pounds of apples = $5
$5 = $1.50(X pounds of pears)
X = 3 1/3 pounds of pears
IF...
A pound of applies costs $.50, then a pound of pears costs $1
5 pounds of applies = $2.50
$2.50 = $1(X pounds of pears)
X = 2.5 pounds of pears
The answer changes based on the starting price of a pound of applies.
Fact 1 is INSUFFICIENT
Fact 2: 1 pound of pears costs 1.5 times as much as 1 pound of apples
IF...
A pound of applies costs $1, then a pound of pears costs $1.50
5 pounds of applies = $5
$5 = $1.50(X pounds of pears)
X = 3 1/3 pounds of pears
A pound of applies costs $2, then a pound of pears costs $3
5 pounds of applies = $10
$10 = $3(X pounds of pears)
X = 3 1/3 pounds of pears
A pound of applies costs $0.50, then a pound of pears costs $0.75
5 pounds of apples = $2.50
$2.50 = $0.75(X pounds of pears)
X = 3 1/3 pounds of pears
In EVERY situation, we end up with the SAME number of pounds of pears.
Fact 2 is SUFFICIENT
Final Answer:
GMAT assassins aren't born, they're made,
Rich
_________________