Each of the members must raise at least $69.46.
To start they need to raise $552.50. However, they have already raised 12% of it. They only need to raise 88% of it.
552.50 x 0.88 = 486.2
Divide the remaining amount by 7 to determine how much each individual must raise.
486.2 / 7 = 69.46
Given:
The function is:

To find:
The value of
.
Solution:
We have,

Putting
, we get



On combining like terms, we get


Therefore, the required function is
.
To solve this we need to use this formula:
a(b+c)=ab+ac
5(7+3x)-12=35+15x-12=15x+23
Answer: Aproximately 2,525 balloons
Step-by-step explanation:
1. Find the volume of a balloon with the formula given in the problem, where
is the radius (
), then:

2. Convert the volume from m³ to lliters by multiplying it by 1,000:

3. You know that that 1 liter of helium can lift 1 gram and that Ryan weighs 5 stone and 5 pounds. So you must make the following conversions:
1 g=0.0022 lb
From 5 stones to pounds

4. Then Ryan's weigh is:
5lb+70lb=75lb
5. Then, if 1 liter of helium can lift 0.0022 lb, to lift 75 lb (which is the weight of Ryan) they need:

6. Then, to calculate the aproximated number of balloons they need to make him float (which can call
), you must divide the liters of helium needed to lift the weight of Ryan by the volume of a balloon, then the result is:

≈2,525 balloons.