The correct option is A 125%
Let the edge =a cm
New edge after increase =a+50%a=a+a2=3a2
Total surface area of original cube =6a2
TSA of new cube =6×(3a2)2=6×9a24=2.25×6a2
TSA=2.25×Total surface area of original cube
Increase in area =[2.25×6a2]−[6a2]=(2.25−1)×6a2=1.25×6a2
∴ Increase in area
=1.25× TSA of original cube
⇒ Increase %=125%