Answer:
72
Step-by-step explanation:
You can find ten percent of 180 pretty easily, it is 18 (divide by 10) then multiply by 4 to get 40%.
Probably you are supposed to compute

Factorize the numerator and denominator, then simplify:
On Saturday - x tickets
on Friday - (x + 100)
altogether
x+x+100=3300
2x=3200
x=1600
x+100=1600+100=1700
1700 on Friday