Answer:
25.9 years
Step-by-step explanation:
The half life of an isotope is related to the actual amounts by the equation:
N = Ni*(1/2)^(t/HL)
where N and Ni are the final and initial (Ni) amounts, t is the time (in years for this problem) and HL is the half-life, in years.
In this problem, we can write:
100 = 360*(1/2)^(x/14)
I'll reduce this to:
1 = 3.6*(1/2)^(x/14)
This can be solved by taking the log of both sides.
x = 25.87 or 25.9 years
Answer:
number of gym members who prefer bicycling : 18/75*350 = 84
number of gym members who prefer exercise classes: 22/75*350 ≈ 103
number of gym members who prefer running on the treadmill: 15/75*350 = 70
number of gym members who prefer weight lifting: 20/75*350 ≈ 93
Step-by-step explanation:
GYM SURVEY RESULTS
Type Number of Members
Bicycling 18
Exercise Classes 22
Running on Treadmill 15
Weight Lifting 20
Total 75
