Problem Solving

Hi Pros,

COuld you please explain to me the logic behind this question? coz when i plugged in numbers i found the answer is E!

At RW Press, the advertising rate, a, is inversely proportional to the productivity measure, b, which, in turn, is inversely proportional to the labor cost, c. Is the labor cost at least 200 when the productivity measure is at least 100?

(1) When c>=100, b>=50

(2) When c= 100,, a = 100

When values are inversely proportional, one goes up when the other goes down.

The question is a little funny, but it's asking whether c is AT LEAST 200 when b is 100. So even if c could be 200 when b is 100, if c does not have to be AT LEAST 200 when b is 100 then, I guess, the answer is "no".

(1) When c ≥ 100, b ≥ 50

c decreases when b increases.

When b ≥ 50, c already does not have to be AT LEAST 200. c only has to be AT LEAST 100.

So when b goes even higher, to b = 100, then c would probably be even lower, and anyway definitely not higher.

So while we don't know how low c is when b is 100, we know that c does not have to be AT LEAST 200.

Sufficient.

(2) When c = 100, a = 100

This tells us nothing new about the relationship between c and b.

Insufficient.

So while the question is a little funny, I guess the correct answer is A.

Marty,

The reason why I thought it would be insufficient is that the statement said greater than or equal.

for example b can be any number greater than 50. it can be 500. same goes with c!

the other way to think about it, is to say when the minimum value for b is 50, the minimum value for c is 100; and hence i could consider it sufficient.

I probably misinterpreted the question!

Marty Murray wrote:When values are inversely proportional, one goes up when the other goes down.

The question is a little funny, but it's asking whether c is AT LEAST 200 when b is 100. So even if c could be 200 when b is 100, if c does not have to be AT LEAST 200 when b is 100 then, I guess, the answer is "no".

(1) When c ≥ 100, b ≥ 50

c decreases when b increases.

When b ≥ 50, c already does not have to be AT LEAST 200. c only has to be AT LEAST 100.

So when b goes even higher, to b = 100, then c would probably be even lower, and anyway definitely not higher.

So while we don't know how low c is when b is 100, we know that c does not have to be AT LEAST 200.

Sufficient.

(2) When c = 100, a = 100

This tells us nothing new about the relationship between c and b.

Insufficient.

So while the question is a little funny, I guess the correct answer is A.

Amrabdelnaby wrote:I probably misinterpreted the question!

What a question, written while the writer was tripping on acid.

Maybe before doing that question we too should have dropped acid.

"If ten lights on the avenue are green and ten are red, what's the name of the zookeeper's pet platypus?"