Is the number y between 0.3 and 0.6 ?

Question

(1) 640y < 320
(2) 800y > 320

GH-08.07.13 | OE to follow.

Bunuel · Answer

Is the number y between 0.3 and 0.6 ? Is 0.3 < y < 0.6? (1) 640y < 320 --> y < 0.5. Not sufficient. (2) 800y > 320 --> y > 0.4. Not sufficient (1)+(2) 0.4 < y < 0.5. Sufficient. Answer: C.

avohden · Answer

Official Explanation

Answer: C Statement (1) is insufficient. Simplify the inequality:
640y/640 < 320/640
y < 0.5
y could be between 0.3 and 0.5, but it could also be less than 0.3.

Statment (2) is also insufficient. Again, simplify:
800y/800 > 320/800
y > 0.4
y could be between 0.4 and 0.6, but it could also be greater than 0.6.

Taken together, the statements are sufficient. If y is less than 0.5 and greater than 0.4, it must be between 0.3 and 0.6. Choice (C) is correct.

adiagr · Answer

Statement 1 640y < 320 y<0.5 Sufficient. Statement 2 800y > 320 y > \frac{32}{80} { \frac{32}{80} = \frac{4}{10} = 0.4 y > 0.4 y can be 0.41, in which case it lies between 0.3 and 0.6. y can be 0.61, in which case it does not lie between 0.3 and 0.6. So statement (2) is not sufficient. Option A is the answer

chetan2u · Answer

Hi,

statement I gives you y<0.5...
and Q asked is --- Is the number y between 0.3 and 0.6 ?
if y is 0.4......ans is YES
But if y is 0.2.... ans is NO

so statement I is not sufficient on its own..

Is the number y between 0.3 and 0.6 ?

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