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If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=

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If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=  [#permalink]

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New post Updated on: 11 Jun 2015, 12:25
2
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A
B
C
D
E

Difficulty:

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Question Stats:

65% (00:39) correct 35% (00:39) wrong based on 252 sessions

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If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=

A. 27
B. 9
C. 3
D. 1
E. 1/3

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Originally posted by reto on 11 Jun 2015, 12:15.
Last edited by Bunuel on 11 Jun 2015, 12:25, edited 1 time in total.
Edited the question.
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If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=  [#permalink]

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New post 11 Jun 2015, 12:24
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Re: If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=  [#permalink]

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New post 11 Jun 2015, 12:28
Bunuel wrote:
reto wrote:
If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=

A. 27
B. 9
C. 3
D. 1
E. 1/3


\(x∇y = 3*x^2*y\)

\(1∇1 = 3*1^2*1=3\)
\(1∇(1∇1)=1∇3 = 3*1^2*3=9\)

Answer: B.


Similar questions: Operations/functions defining algebraic/arithmetic expressions
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If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=  [#permalink]

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New post Updated on: 04 Jun 2016, 13:59
1
I first thought the question stem said 3x^2 - Y. So, i guess everyone should be careful and note that there is no subtraction sign but that it is a multiplication (*) sign--- meaning : 3x^2 * Y.

Regardless of that note, yes the answer is 9! (B)

Originally posted by acarpio1 on 04 Jun 2016, 13:57.
Last edited by acarpio1 on 04 Jun 2016, 13:59, edited 1 time in total.
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Re: If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=  [#permalink]

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New post 07 Jan 2019, 11:52
I haven't understood the question stem itself, can someone explain theoretically what does the question actually imply? :cry:
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Re: If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=  [#permalink]

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New post 07 Jan 2019, 22:15
1
Shef08 wrote:
I haven't understood the question stem itself, can someone explain theoretically what does the question actually imply? :cry:


If x∇y=3x^2·y for all x and y, then 1∇(1∇1)=

A. 27
B. 9
C. 3
D. 1
E. 1/3

Symbol ∇ here indicates a function, which does the following: for any two numbers x and y, x∇y equals to 3x^2*y. For example, if x = 5 and y = 10, then 5∇10 = 3*5^2*10 = 750.

The question asks to find the value of 1∇(1∇1). First deal with expression in brackets: (1∇1) = 3*1^2*1 = 3. So, now we should find the value of 1∇3, which is 3*1^2*3 = 9.

Answer: B.

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Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


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Re: If x∇y=3x^2·y for all x and y, then 1∇(1∇1)= &nbs [#permalink] 07 Jan 2019, 22:15
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