What is the difference between
increase $5000 by 20%

and

decrease $5000 by 20%

20% of $5000 = (20/100) x $5000 = $1000

This means 20% increase = $5000 + $1000 = $6000
This means 20% decrease = $5000 - $1000 = $4000

Difference between these = $6000 - $4000 = $2000

In the first triangle 80+20+p=180 (since sum of all angles of a triangle is 180)so p= 80also in second triangle 55+45+q=180 (since sum of all angles of a triangle is 180)so q=80so we can conclude that p=80 degrees q=80 degrees so p=q=80 degreeshence option b is correct