Question

If ${\log }_{10}2=0.301\&{\log }_{10}3=0.477$, then the number of digits in the number $N=3^{12}\times 2^8$ is equal to

• A. 9
• B. 8
• C. 7
• D. 5

Answer 1

Answer: (A)

$N=3^{12}\times 2^8$
${\log }_{10}N=12{\log }_{10}3+8{\log }_{10}2$
$=12\times 0.477+8\times 0.301$
$=5.724+2.408$
$\text{ char }=8\therefore \text{ number of digits }=9$