probability again
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[spoiler]1/5[/spoiler]
including 0 (non-negative and non-positive) N can be 10 values
for 5N^3/8 to be an integer N must be an integer when N^1/8 as 5 is the prime number and the power of 3/8 cannot be further reduced. Hence N can be 0 and 1 only
so we get 2 good selections out of 10 possibilities or 1/5
including 0 (non-negative and non-positive) N can be 10 values
for 5N^3/8 to be an integer N must be an integer when N^1/8 as 5 is the prime number and the power of 3/8 cannot be further reduced. Hence N can be 0 and 1 only
so we get 2 good selections out of 10 possibilities or 1/5
jayanti wrote:if number N is randomly drawn from a set of all non-negative single digit integers what is the probability that 5N^3/8 is an integer
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[spoiler]1/5[/spoiler]
(5/8)x(N^3)=int
For only N=0,2 from {0,1,2,...,9} the above condition is satisfied.
(5/8)x(N^3)=int
For only N=0,2 from {0,1,2,...,9} the above condition is satisfied.
- Bek
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I got 1/2
All non-negative single digit integers: 0,1,2,3,4,5,6,7,8,9
5N^3/8 = integer
5*0^3/8 = 0
5*2^3/8 = 5
5*4^3/8 = 40
5*6^3/8 = 60
5*8^3/8 = 320
The probability that 5N^3/8 = an integer is 5/10 or 1/2
All non-negative single digit integers: 0,1,2,3,4,5,6,7,8,9
5N^3/8 = integer
5*0^3/8 = 0
5*2^3/8 = 5
5*4^3/8 = 40
5*6^3/8 = 60
5*8^3/8 = 320
The probability that 5N^3/8 = an integer is 5/10 or 1/2
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The quotient is not clear. Please use paranthesis where ever necessary
I see two kinds: (a) 5*(N^3)/8 (b) 5*N^(3/8)
I see two kinds: (a) 5*(N^3)/8 (b) 5*N^(3/8)
- bblast
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sample space is {0,1,2,3,4,5,6,7,8,9} = 10 numbers
for 5 * N cube to be divisible by 8, N must be divisible by 2
thus favorable cases - {0,2,4,6,8} - remember 0 is divisible by any integer. i.e 0/N = Integer (for all N).
required prob = 1/2
for 5 * N cube to be divisible by 8, N must be divisible by 2
thus favorable cases - {0,2,4,6,8} - remember 0 is divisible by any integer. i.e 0/N = Integer (for all N).
required prob = 1/2
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I'm a little confused. If non negatives are to be considered why are we including 0 in the sample space.
For me the answer is 4/9.
Expert help would be appreciated.
For me the answer is 4/9.
Expert help would be appreciated.
- bblast
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Hi, always remember that 0 is neither positive nor negative.BABAMANALI wrote:I'm a little confused. If non negatives are to be considered why are we including 0 in the sample space.
For me the answer is 4/9.
Expert help would be appreciated.
0 is even.
0/any number = integer.
any number/0 = undefined.
0^0 is undefined - never test this case in DS
0! = 1
any number^0 = 1.
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Quant 47-Striving for 50
Verbal 34-Striving for 40
My gmat journey :
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My take on the GMAT RC :
https://www.beatthegmat.com/ways-to-bbla ... 90808.html
How to prepare before your MBA:
https://www.youtube.com/watch?v=upz46D7 ... TWBZF14TKW_