Answer:
A sixth grade silence club needs 180$ to pay for the tickets to a science museum.
1. Suppose there 15 students in the club, then each of them needs to pay
\dfrac{\$180}{15}=\$12
15
$180
=$12
This means each ticket costs $12.
2. Suppose each ticket cost $15, then there are
\dfrac{\$180}{\$15}=12
$15
$180
=12 students in the club.