What is the value of t? $$(1)\ \ \ \ \ t(t-1)^2=4t\ .$$ $$(2)\ \ \ t\ \ is\ an\ \ integer.$$ The OA is E.
Experts, using both statements is not sufficient? I think the answer should be C. Am I wrong?
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What is the value of t?
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GMATGuruNY
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Statements combined:VJesus12 wrote:What is the value of t? $$(1)\ \ \ \ \ t(t-1)^2=4t\ .$$ $$(2)\ \ \ t\ \ is\ an\ \ integer.$$ The OA is E.
Experts, using both statements is not sufficient? I think the answer should be C. Am I wrong?
Test easy integer values for t (0, 1, 2, 3, etc.).
t(t-1)² = 4t is satisfied by both t=0 and t=3.
Since t can be different values, INSUFFICIENT.
The correct answer is E.
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We need to determine the value of t.VJesus12 wrote:What is the value of t? $$(1)\ \ \ \ \ t(t-1)^2=4t\ .$$ $$(2)\ \ \ t\ \ is\ an\ \ integer.$$
Statement One Alone:
t(t - 1)^2 = 4t
Simplifying we have:
t(t^2 - 2t + 1) = 4t
t^3 - 2t^2 + t = 4t
t^3 - 2t^2 - 3t = 0
t(t^2 - 2t - 3) = 0
t(t - 3)(t + 1) = 0
t = 0 or 3 or -1
Statement one alone is not sufficient to answer the question.
Statement Two Alone:
t is an integer
Statement two alone is not sufficient to answer the question.
Statements One and Two Together:
Using both statements we still see that t = 0 or 3 or -1.
Answer: E
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