Answer:
1)
Let the number of guests = x
∴ Pin hall total charge = 500 + 15x
Bloom place total charge = 350 + 18x
2)
The charges are equal.
∴ 500 + 15x = 350 + 18x
⇒ 150 = 3x
⇒ 50 = x
∴ x = 50
This means that the charges for both halls will be equal when there are 50 guests.