The answer should be A. In order to solve these half-life problems, I encourage you to find an algebra calculator online, and plug in these numbers. The remaining grams goes in front, so 3.
The entire equation should look something like 3 = 15(1/2)^t/4.95
The 4.95 represents how long it takes before the sample halves, t is your answer, 1/2 represents the value halving every 4.95 hours, 15 is the initial sample size, and 3 is the end result that remains.
The overall answer should be about 11.5 hours, as per an algebra calculator.
Hope this helps solve any other similar problems
Considering the perimeter (P)

where b is the base and h is the height, then

Being the area (A)
Answer:
Width = 4 m
Length = 7 m
Step-by-step explanation:
given:
perimeter of a rectangle = 22m
L = 3 + W
perimeter = 2L + 2W
perimeter = 2 (3 + W) + 2W
22 = 6 + 2W + 2W
22 - 6 = 4W
W = 16 / 4
W = 4 m
L = 3 + W
L = 3 + 4
L = 7 m
check:
perimeter = 2L + 2W
22 = 2(7) + 2(4)
22 = 14 + 8
22 = 22 ---- OK
The answer to this question is 8-2.
2 5/6 = 2.83
1 3/4 = 1.75
2.83*1.75= 4.9525