If b0, which of the following cannot be true if b,c and d

Question

If b < c < d and c > 0 , which of the following cannot be true if b, c and d are integers? A. bcd > 0 B. b + cd < 0 C. b – cd > 0 D. \frac{b}{cd} < 0 E. b^{3} cd < 0

sillyboy · Answer

b0 => either b>0 or b<0 A.bcd>0. POSSIBLE if b>0 B.b+cd<0. POSSIBLE if b= -10, c=2, d=3 C.b–cd>0. NOT POSSIBLE. D.bcd<0. POSSIBLE if b<0 E.(b^3)cd<0. POSSIBLE if b<0 Therefore, C.

BillyZ · Answer

https://uploads.tapatalk-cdn.com/20170120/5f9605e8aafdddcc8ba5d1d5aaf33d61.jpg

I have tested by using different sets of value to verify the result.

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roadrunner · Answer

b< c < d && c> 0 ==> d>0 && (b<0 or b>0) since c & d are greater than 0 ==> cd > 0 && cd > b Thus, b - cd > 0 is not possible. Ans.: C

Shiv2016 · Answer

b can be 0 as we are not given that b,c,d are positive integers.

Thus only choice C fits.

ScottTargetTestPrep · Answer

We are given that b < c < d and c > 0, and that b, c, and d are integers. Since c > 0, c is positive, and since d > c, d must also be positive. However, we are unsure of whether b is positive or negative. Let’s look at our answer choices to determine which MUST be true. A. bcd > 0 If b is positive, then bcd is greater than zero. Answer choice A can be true. B. b + cd < 0 If b is negative and its absolute value is greater than the product of cd, then b + cd is less than zero. For example, if b = -3, c = 1, and d = 2, we have -3 + (1)(2) = -1 < 0. Answer choice B can be true. C. b - cd > 0 We can simplify answer choice C to read: b > cd If b is negative or zero, it certainly can’t be greater than cd, since cd is positive. If b is positive, it still can’t be greater than cd, since both c and d are integers greater than b. Thus, answer choice C can never be true. Answer: C

GMATBusters · Answer

This question can be done by this approach.
The key point is that  b can be greater than , equal to or less than zero.

bumpbot · Answer

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If b<c<d and c>0, which of the following cannot be true if b,c and d

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