To calculate the remaining caffeine, we use the radioactive decay formula which is expressed as An = Aoe^-kt where An is the amount left after t time, Ao is the initial amount and k is a constant we can calculate from the half-life information. We do as follows:
at half-life,
ln 1/2 = -k(6)
k = 0.12/hr
An = 80e^-0.12(14)
An = 15.87 mg
the answer that I came up with is (c)
Convert the larger unit into the smaller unit, and then solve.
The graph looks accurate make sure you create a table of values and clearly dot the points at (0,-3) and (2,-3).
5 'parts' of the total company staff are men, and 8 'parts' are women.
That's 13 'parts' all together, comprising 364 people.
So each 'part' is 364/13 = 28 people.
Men = 5 'parts' = 5 x 28 = <u>140 men</u>
Women = 8 'parts' = 8 x 28 = <u>224 women</u>
<em><u>Check:</u></em>
140/224 = 70/112 = 35/56 =<em> </em><em>5/8</em>
140 + 224 = <em>364</em>
yay !
