Answer:
$ 54
Explanation:
Barbara bought :
5 tickets ⇒ $ 30
And now let the costs of 9 tickets be x :
9 tickets ⇒ $ x
So,
5 tickets ⇒ $ 30
9 tickets ⇒ $ x
Now use cross multiplication to find the value of x :
5 x = 9 × 30
5 x = 270
Now divide both sides by 5.
x = $ 54
Hope this helps you :-)
Let me know if you have any other questions :-)