Cynthia made the conjecture that the sum of any prime number and any composite number is a composite number.
which equation is a counterexample to her conjecture?
a.
11 + 2 = 13
b.
5 + 8 = 13
c.
13 + 2 = 15
d.
11 + 9 = 20

c(x)= 6x + 3

step-by-step explanation:

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

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