Doubt in a math question

I have been looking into the recordings of Greg mat and I can’t figure out why the %increase is 100?

This is the question :

I thought the answer is 300%. Let me know if I am wrong or am I missing something here?

Q1 would be:
if you assume unknown percentage as p
30 = 15 X p/100
30*100 = 15 X p
3000 /15 = p
200 = p
Thus, p=200%

Q2 would be:
Percentage Increase =( (Big Number−Small Number)/(Small Number )) * 100 percent
=( (30-15)/15) * 100 percent
= (15/15) * 100 percent
= 1 * 100 percent
= 100 percent
I hope this helps @iam_venkat03

hi @user514
In Q2, the smaller number is -15 and not 15.
So, doesn’t (Big no - small no) became (30-(-15)) = (45/15)*100 = 300%?

it is just hyphen it is there in first question too @iam_venkat03

Yeah. But even if it’s -30 in the Q1, its still 200%. But if I consider -15 or 15 in the Q2 the whole answer changes.