Answer:
20 tickets.
Explanation:
Given:
After selling 200 tickets, they made a profit of $12,000.
Question asked:
How many more tickets it must be sold by charity to cover the cost of $1,200 ?
Solution:
First of all we will calculate profit earned by selling 1 ticket.
By unitary method:
After selling 200 tickets, they made a profit = $12,000.
After selling 1 ticket, they made a profit =
![(12000)/(200) =\$60](https://img.qammunity.org/2021/formulas/mathematics/high-school/9i84tf3sjtlal3yu4pggquy00e8u5dm4oi.png)
Now, we have to find number of more tickets must be sold to cover to cost of $1200.
It is clear that cost must be cover by earning profits, so to earn $1200 as profit we have to sell number of tickets:-
By unitary method:
Amount of profit must be earned divided by profit earned from each ticket,
![(1200)/(60) =20\ tickets](https://img.qammunity.org/2021/formulas/mathematics/high-school/plq9n1acex27bso8jg33327kn1uh3dbqvj.png)
Therefore, they had to sell 20 more tickets to cover necessary cost of $1,200.