If 20% of a number is 35, what is 50% of that number?

87.50

Step-by-step explanation:

Let x be the required number,

Then 20% of x = = 0.20x

According to the question,

20% of x = 35

Divide both sides by 0.20

Thus, the required number is 175,

Now, 50% of 175 =

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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