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praveen_gmat
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Eighty percent of the lights at Hotel California are on at 8 p.m. a certain evening. However, forty percent of the lights that are supposed to be off are actually on and ten percent of the lights that are supposed to be on are actually off. What percent of the lights that are on are supposed to be off?
A) 22(2/9)%
B) 16(2/3)%
C) 11(1/9)%
D) 10%
E) 5%
Answer is D
The solution I arrived at is
My doubt is:
when the question is asking What percent of the lights that are on are supposed to be off
then .. the we should be looking for:
Supposed to be off =
{ supposed to be off but actually ON}
+
{ supposed to be off and actually OFF}
Why are we taking 8/80 as the solution as 8 corresponds to the value that is only supposed to off but actually ON ?
Hope somebody can clarify my doubt ![/b]
A) 22(2/9)%
B) 16(2/3)%
C) 11(1/9)%
D) 10%
E) 5%
Answer is D
The solution I arrived at is
My doubt is:
when the question is asking What percent of the lights that are on are supposed to be off
then .. the we should be looking for:
Supposed to be off =
{ supposed to be off but actually ON}
+
{ supposed to be off and actually OFF}
Why are we taking 8/80 as the solution as 8 corresponds to the value that is only supposed to off but actually ON ?
Hope somebody can clarify my doubt ![/b]
