Answer:
11,200
Step-by-step explanation:
At first we use "BODMAS" rule.
Given,
(3.5×10^13)-(1.4×10^12)/3×10^9
So, we will break the brackets at first. With the help of excel, we can get the desired result. The following images will show you the step-by-step result.
Use "Number" instead of "general" in the excel sheet. You can use calculator too.
63
This is because 25% of 84 is 21. He knows how to play 21 songs. 84-21=63.
63 is how many songs he does NOT know how to play.
B