Both a and b are positive; what is the value of a?
(1) 150 percent of a equals 450 percent of b.
(2) ab is the cube of a positive integer.
why is it not C
statement 1: 1,5a=4.5b or a=3 b
statement 2: ab= x^3 surely insufficient
1+2
ab=3b^2=x^3 so only b = 3 and since b =3 we can find a, right?
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diebeatsthegmat
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(1) 150% of a = 450% of bdiebeatsthegmat wrote:Both a and b are positive; what is the value of a?
(1) 150 percent of a equals 450 percent of b.
(2) ab is the cube of a positive integer.
why is it not C
statement 1: 1,5a=4.5b or a=3 b
statement 2: ab= x^3 surely insufficient
1+2
ab=3b^2=x^3 so only b = 3 and since b =3 we can find a, right?
1.5a = 4.5b implies a = 3b; we don't know b, so cannot find a definite value of a; NOT sufficient.
(2) ab = x^3, where x is any positive integer; NOT sufficient.
Combining (1) and (2), 3b² = x^3
Now it is given that both a and b are positive, so they can be positive fractions or integers.
So, combining the statements also is NOT sufficient.
The correct answer is E.
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cans
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A) 150a = 450b or a=3b
insufficient
B) ab is cube. insufficient
A*B) ab = 3b^2 is cube. b=3 will do, also b = 24 will do... insufficient
IMO E
insufficient
B) ab is cube. insufficient
A*B) ab = 3b^2 is cube. b=3 will do, also b = 24 will do... insufficient
IMO E
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Cans!!
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diebeatsthegmat
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oh yeah! i forgot "fraction" problem... thank you. you are so amazing!Anurag@Gurome wrote:(1) 150% of a = 450% of bdiebeatsthegmat wrote:Both a and b are positive; what is the value of a?
(1) 150 percent of a equals 450 percent of b.
(2) ab is the cube of a positive integer.
why is it not C
statement 1: 1,5a=4.5b or a=3 b
statement 2: ab= x^3 surely insufficient
1+2
ab=3b^2=x^3 so only b = 3 and since b =3 we can find a, right?
1.5a = 4.5b implies a = 3b; we don't know b, so cannot find a definite value of a; NOT sufficient.
(2) ab = x^3, where x is any positive integer; NOT sufficient.
Combining (1) and (2), 3b² = x^3
Now it is given that both a and b are positive, so they can be positive fractions or integers.
So, combining the statements also is NOT sufficient.
The correct answer is E.
