Using an exponential function, it is found that:
a) 
b) 37.5 grams of the gas remains after 3.8 days.
c) The amount remaining will be of 10 grams after approximately 11 days.
<h3>What is an exponential function?</h3>
A decaying exponential function is modeled by:

In which:
- A(0) is the initial value.
- r is the decay rate, as a decimal.
Item a:
We start with 75 grams, and then work with a half-life of 3.8 days, hence the amount after t daus is given by:

Item b:
This is N when t = 3.8, hence:

37.5 grams of the gas remains after 3.8 days.
Item c:
This is t for which N(t) = 10, hence:







The amount remaining will be of 10 grams after approximately 11 days.
More can be learned about exponential functions at brainly.com/question/25537936
Answer: 2 inch dimension will give smallest increase.
Step-by-step explanation:
Length = 3 in
width = 2 in
height = 6 in
Extra cardboard means to find surface area
on doubling the length
length = 6 In
width = 2 In
Height = 6In
Surface area for the above dimensions = 2 [ 6x2+2x6+6x6] = 120 sq in
On doubling the width
length = 3 in
width = 4 in
Height = 6 inch
Surface area for the above dimensions= 2 [ 3x4+4x6+6x3] = 2[54] = 108 sq inches
On doubling height
Length =3 in
width = 2 in
Height = 12 in
Surface area for above dimensions = 2 [ 3x2+2x12+12x3] = 2[6+24+36] = 132 sq inch
On doubling width surface area is minimum.
The answer should be C but you posted this in the wrong category.
11 8/2 + 2 3/8 = 30/2 + 19/8 = 15 + 2,375 = 17,375