Value of k

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Value of k

by kanha81 » Mon Mar 02, 2009 10:14 am
q: k>0, k is an integer & n=7.049*(10^k), what is value of k?

i) 7,500 < n < 75,000
ii) 10^4 < n < 10^5
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by scoobydooby » Mon Mar 02, 2009 10:22 am
n=7.049*(10^k)

stmnt 1: 7,500 < n < 75,000
n can take any value from 7501 to 74999, depending on the value of n, k can have multiple values, we do not get any definite value of k.
not sufficient


stmnt 2: 10^4 < n < 10^5
n can take any value from 10,001 to 99,999 and k therefore can have multiple values.
not sufficient

together 7,500 < n < 75,000
no additional info obtained
hence E

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by kanha81 » Mon Mar 02, 2009 10:53 am
scoobydooby wrote:n=7.049*(10^k)

stmnt 1: 7,500 < n < 75,000
n can take any value from 7501 to 74999, depending on the value of n, k can have multiple values, we do not get any definite value of k.
not sufficient


stmnt 2: 10^4 < n < 10^5
n can take any value from 10,001 to 99,999 and k therefore can have multiple values.
not sufficient

together 7,500 < n < 75,000
no additional info obtained
hence E
Sorry scoobydooby, the OA is not E.
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by Sher1 » Mon Mar 02, 2009 11:03 am
The answer is D

St1:

7500<n<75000
7500<7.049*10^k<75000
K=4
if k = 4
n=70,490 which is within the constraint
is k=5
n=704,900 which is >75,000
if k=3
n=7049 which is <7500

st2
10,000<n<100,000
10,000<7.049*10^k<75000
k=4
if k=4
n=70,490 which is within then constraint
if k=5
n=704900 which >than 100000
if k=3
n=7049 which is <than 10000