A charter airline finds that on its Saturday flights from Philadelphia to London all 180 seats will be sold if the ticket price is $200. However, for each $3 increase in ticket price, the number of seats sold decreases by one. (a) Find a formula for the number of seats sold S if the ticket price is P dollars.

Step-by-step explanation:

Given that:

Number of seats sold is 180 with ticket price $200.

Number of seats decreases by one when the ticket price is increased by $3.

To find:

The formula for the number of seats sold (S) when the ticket price is P dollars.

Solution:

It is linear dependency of number of seats sold, S on ticket price, P.

It can be written as:

Where is the constant of proportionality and

is a constant.

Now, putting the given values:

...... (2)

Subtracting (1) from (2):

Putting the value in (1):

Therefore the equation becomes:

b.-4 units

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