I believe that b.Fractions are rational numbers is not true
sorry if its wrong

check your calculator for the [!] factorial button.
also bear in mind that most calculators also have an [ₙPᵣ] button, to get Permuations, and you can just use that.
11, count everything after 3 and everything before 4
Decimal Exact form: 25/6
It is a terminating decimal
Answer:
x=50
Step-by-step explanation:
3x+30=180
3x=150
x=50