The <em>correct answer</em> is:
6 balloons.
Explanation:
Let x represent the number of balloons purchased.
We will call the function for Clowns R Fun c(x):
c(x) = 1.25x+6
We will call the function for Singing Balloons s(x):
s(x) = 1.95x+2
We want the amount for Clowns R Fun, c(x) to be less:
c(x) < s(x)
1.25x+6 < 1.95x+2
Subtract 1.25x from each side:
1.25x+6-1.25x < 1.95x+2-1.25x
6 < 0.7x+2
Subtract 2 from each side:
6-2 < 0.7x+2-2
4 < 0.7x
Divide each side by 0.7:
4/0.7 < 0.7x/0.7
5.7 < x
x > 5.7
She must buy more than 5.7 balloons; the next integer up is 6. She must buy 6 or more balloons.
10 books cost $30. To figure it out, it's just 3 times the number of books. XD
Answer:
The lower bound of 19.4 is 19.35
