Answer:
$11 and $16
Step-by-step explanation:
let x be the cost of a student ticket then an adult ticket is x + 5 , then
3x + 7(x + 5) = 145 , that is
3x + 7x + 35 = 145
10x + 35 = 145 ( subtract 35 from both sides )
10x = 110 ( divide both sides by 10 )
x = 11
Student ticket costs $11 and adult ticket = x + 5 = 11 + 5 = $16
Let
denote the <em>k</em>th term of the sequence. Then

where <em>d</em> is the common difference between consecutive terms in the sequence and <em>a</em>₁ is the first term.
The sum of the first <em>n</em> terms is

From the formula for
, we get




So we have
, and
so that
.
Then the <em>n</em>th term in the sequence is
