Elitmus
Exam
Numerical Ability
Log and Antilog
log3 N+log9 N what is 3 digit number N that will be whole number
Read Solution (Total 8)
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- No of values N can take is 1
9^3=729 - 9 years agoHelpfull: Yes(9) No(1)
- 729 was not an option
- 9 years agoHelpfull: Yes(3) No(0)
- 3log N base 9=whole number when N=9,81,729,6561
so ans will 729
- 9 years agoHelpfull: Yes(2) No(0)
- log3N+1/2log3N=odd
log3N()1+1/2)=odd
log3N(3/2)=odd
N=243 or 728
but only 729 is satisfying
so N=729 - 9 years agoHelpfull: Yes(1) No(1)
- 729 will be the answer
- 9 years agoHelpfull: Yes(0) No(0)
- BREIFly explain please
- 9 years agoHelpfull: Yes(0) No(0)
- 36=729
93=729
log3729+log9729
log336+log993
6log33+3log99
9
- 9 years agoHelpfull: Yes(0) No(0)
- log3N + log3N/log 9 base 3 [ using base change property]
log3N + log3N - log 9 base 3
2log3N = log 9 base 3
log 3 N^2 = log 9 base 3
N^2 = 9 [ log cancelled out] - 7 years agoHelpfull: Yes(0) No(1)
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