A certain radioactive element has a half-life of 30 years. How long does it take for an 80-gram sample to decay to 20 grams? Explain why you do not need your calculator to solve this problem.
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Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)

Edger needs 6 cookies and 2 brownies for every 4 plates how many cookies and brownies does he need for 10 plates