To find the total playtime of Jim's music library in seconds, we can follow these steps:
-
Calculate the total playtime in minutes: \[ \text{Total playtime in minutes} = \text{Number of songs} \times \text{Average time per song} \] \[ = 1900 , \text{songs} \times 3.5 , \text{minutes/song} = 6650 , \text{minutes} \]
-
Convert the total playtime to seconds: Since there are 60 seconds in a minute, we multiply the total playtime in minutes by 60: \[ \text{Total playtime in seconds} = 6650 , \text{minutes} \times 60 , \text{seconds/minute} = 399000 , \text{seconds} \]
-
Express this number in scientific notation: \[ 399000 = 3.99000 \times 10^5 \text{ seconds} \] We can round this to three significant figures: \[ 3.99 \times 10^5 \text{ seconds} \]
So, the total playtime of Jim's music library is \( \mathbf{3.99 \times 10^5} \) seconds.