By what percent will the fraction change if its numerator is increased by 25% and its denominator is increased by 20%?

Lets take fraction
a/b
When numerator is increased by 25%, it is going to be 
(a+0.25a)=1.25a
When denominator is increased by 20% , it is going to be (b+0.2b)=1.2b

New fraction (1.25a/1.2b) = 125a/120b=(125/120)*(a/b)=
=(25/24)(a/b)≈1.0417(a/b)= 1(a/b)+0.047(a/b)
0.047=4.7 %

I’m not sure what it is i sorry : ((