Given :
Initial concentration , 240 ppm .
Final concentration , 360 ppm .
To Find :
Percent increase.
Solution :
Percentage increase is given by :
[tex]=\dfrac{Final-Initial}{Initial}\times 100\\\\=\dfrac{360-240}{240}\times 100\\\\=50\%[/tex]
Therefore , percent increase is 50 % .
Hence , this is the required solution .