Hi!
To solve this problem you can set up a proportion (I like doing it this way) or you can just do:
First deal:
(24/3)*5 = 40 dollars
Second deal:
(24/4)*6 = 36 dollars
Finding money saved:
40-36 =4
They will save 4 dollars buying the second 4 for 6 dollars deal!
$10.71
Explanation
Step 1
you can easily solve this by using a rule of three.
Let
x represents the money Eileen will pay if her bag weighs 63 pounds
the proportion is the same
then
Step 2
solve for x
I hope this helps you
A₁ = 9
a₂ = 9+2 → a₂ = a₁ + 2. Since it's an AP, d, the common difference is 2
1) Then the recursive formula is :
a(n) = a(n-1) + 2
2) Explicit formula:
It's an AP, with first term a₁, d= common difference and n = number of term, which is the number of rows in this problem.
the value of the nth term is given by the formula is:
value of nth term = a₁ + (n-1).d
3) Number of seats in the 12th row:
9 + (12-1).2 = 31 seats