If the operation ? is defined by x?y = yx^(1/2) for all positive

Question

Competition Mode Question

If the operation ? is defined by  x?y = y\sqrt{x}  for all positive integers x and y, then  9?(16?25) =

A. 60

B. 180

C. 240

D. 300

E. 1200

anbknaga · Answer

x?y = y \sqrt{x}

9?(16?25)

Parenthesis first:
9?(25 \sqrt{16} )
=> 9?(25*4)
=> 9?(100)
=> 100 \sqrt{9} 
=> 100*3 = 300

The answer is  D

eakabuah · Answer

x?y=y(x)^(1/2) 
9?(16?25) = 9?(25*4) = 100*3 = 300
Answer is therefore D.

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Kinshook · Answer

Given:  The operation ? is defined by x?y=y√x for all positive integers x and y,

Asked:  9?(16?25)=

16?25 = 25√16 = 25*4 =100
9?100 = 100√9 = 100*3 = 300

IMO D

Ilishar · Answer

Given: x?y = y(x)^1/2

9?(16?25)
9?(25(16)^1/2)
9?(25*4)
9?(100)
100(9)^1/2
100*3
300
ans is D

saukrit · Answer

9?(16?25)=

= 9?(25 \sqrt{16})

= 9? (25*4)

= 9?100

= 100\sqrt{9}

=100*3

300   ANSWER

EncounterGMAT · Answer

The operation ? is defined by x?y=y√x for all positive integers x and y, then 9?(16?25)=?

first lets solve 16?25=25√16=25*4=100

9?100=100√9=100*3=300......OPTION D

rishinric · Answer

If the operation ? is defined by $x?y = y\sqrt{x}$ for all positive integers x and y, then $9?(16?25) =$
16?25= 25xsquare root of 16
=25x4
=100
Then 9?100= 100xsquare root of 9
= 300
Answer D

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mira93 · Answer

Let's take care of the first expression 16?25=25  \sqrt{16} =25*4=100. 
Now, we have 9?100 or 100 \sqrt{9} =100*3= 300 (D)

bebs · Answer

Let us tackle the parentheses first: (16?25) = 25 ×  16^{1/2}  = 25 × 4 = 100

Next: 9?100 = 100 ×  9^{1/2}  = 100 × 3 = 300

The answer is   D

ccheryn · Answer

If the operation ? is defined by x?y = yx^(1/2) for all positive 25 integers x and y, then 9?(16?25)=

16?25 gives 25 x squre root of 16 = 100

now 9?100 gives 100 x square root of 9 = 300

hence ans D is correct choice

Kumar Utkarsh · Answer

9?(16?25)=9?(25*sqrt 16)=9?(25*4)=9?100=100*sqrt 9=100*3=300

unraveled · Answer

9?(16?25) equates to 9?(x?y) where x = 16 and y = 25
 9?(y√x)
 9?(25√16)
 9? (25x4)
 9?100
 100√9
 100x3
 300
Answer(D)

Mayank1996 · Answer

If the operation ? is defined by x?y=y√x for all positive integers x and y, then 9?(16?25)

Given : x?y=y√x (only for positive integers)

To Find : 9?(16?25)

Solution : Lets take Z= (16?25) first.
Lets say, X=16 and Y=25

Now we know that x?y=y√x
So, (16?25) = 25√16 => 25*4 => 100
Now we have Z=100 and we are left with 9?(Z), (Z=100)
so now, X=9, Y=100
9?(100) = 100√9 = 100*3 = 300

IMO

D. 300

Karmesh · Answer

This is a fairly simple question, so let's jump into it.
according to question x?y = y(x)^1/2 
 9?(16?25) --> Let's start with the brackets

16?25 = 25*(16)^1/2= 100
So question now simplifies to 9?100
100*(9)^1/2 = 100*3 = 300

Archit3110 · Answer

If the operation ? is defined by x?y=yx√x?y=yx for all positive integers x and y, then 9?(16?25)=9?(16?25)=

A. 60

B. 180

C. 240

D. 300

E. 1200

expression can be solve ; 
25√16; 100
9?100 ' 100 √9 ; 300
IMO D

J2S2019 · Answer

If the operation ? is defined by x?y=y√x for all positive integers x and y, then 9?(16?25)=

A. 60

B. 180

C. 240

D. 300

E. 1200

9?(16?25)=9?(25 * 16^1/2)=9?(25*4)=9?100=100*9^1/2=100*3=300

komals06 · Answer

Given: x?y=yx^1/2

9?(16?25)

Lets start from parenthesis 16?25 compare it with definition of ?. our x is 16 and y is 25. 
so,
16?25 = 25 * 16 ^1/2
 = 100
Now coming to 9?100 , again x=9 and Y= 100
9?100= 100* 9^1/2
 = 100*3
  = 300

And choice D

shuvodip04 · Answer

16?25 = 25 * \sqrt{16} = 25 * 4 =100

Again,

9?100 = 100 *\sqrt{9} = 100 * 3 = 300 (D)

TheNightKing · Answer

9?(16?25) works out to be 25root16 which is 100.
9?100 is 100root9 which works out to be 300.
IMO D

If the operation ? is defined by x?y = yx^(1/2) for all positive

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If the operation ? is defined by x?y = yx^(1/2) for all positive

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