The initial height of the balloon is 10 feet which then increases by 70% to (10 ×1.7) = 17 feet, then to (17 × 1.7) =28.9 feet, and so fourth if the rate of increase is kept constant. Therefore, forming a geometric sequence such that to get any term in the sequence we use the formula ar∧(n-1), where a is the first term, r is the common ratio, and n is the term in the sequence. In this case a is 10 and r= 1.7 , to get the height in the fourth minute it means n =5 (for the first term there is 0 minutes, such that for 0 minutes n= 1)
Thus, 10 × 1.7 ∧ 4 = 83.521 feet.
Therefore, the answer is 83.521 feet
Answer:
Then the total area is 116 cm^2 which agrees with answer D
Step-by-step explanation:
Notice we need to calculate the area of two rectangles (one larger at the bottom and a smaller one on top)
The Area of a rectangle is the product: base x height
In our case :
Area of Big rectangle = 12 cm x 7 cm = 84 cm^2
Area of smaller rectangle = 8 cm x 4 cm = 32 cm^2
Then the total area is: 84 cm^2 + 32 cm^2 = 116 cm^2
$65.80
$26.32/8=$3.29 for a gallon
$3.29 x 20 = $65.80.
Hope this helps