# Question #199a9

Dec 8, 2016

$60$dB

#### Explanation:

Given that Sound level of a piano is 50dB.

Total Sound level of $n$ similar pianos will be $n \times$ the level of each piano. We know that $n \times$ can be written in dB as
$10 {\log}_{10} n$
In the given problem $n = 10$
Therefore $10 \times$
$= 10 {\log}_{10} 10$ dB
$= 10 \times 1$ dB
$= 10$ dB

Total Sound level of $10$ similar pianos will be$= 50 + 10 = 60$dB