To calculate what is asked we use the formula for radioactive decay. It is expressed as follows:
An = Ao (e^(-kt))
We calculate as follows:
An = Ao (e^(-kt))
74 = 100 (e^(-k(10)))
k = 0.0301
1/2 = (e^(-0.0301t))
t = 23 hours
Hope this answers the question.
Answer: the answer is C
Step-by-step explanation:
7.2 x 6=43.2 cm^2
(2.8+7.2) x 4 /2 = 20 cm^2
20+43.2=63.2 cm^2
Answer:

x = 0.36
Step-by-step explanation:
5x/3 + 2/5 = 1
5x/3 + 2/5 - 2/5 = 1 - 2/5

5x/3 × 3 = 0.6 × 3
5x = 1.8
5x ÷ 5 = 1.8 ÷ 5

x = 0.36
Answer:
To find the sum of an infinite geometric series having ratios with an absolute value less than one, use the formula, S=a11−r , where a1 is the first term and r is the common ratio.
Answer:
B
Step-by-step explanation:
(r^-7)^6 = r^-42 = 1/r^42