Answer:
3
y
(
2
x
−
1
)
(
x
−
4
y
)
Step-by-step explanation:
The general way to work this out is to solve the general expression for
the remaining quantity versus half-life, using logarithms. But that's not
necessary with these numbers.
Look at the numbers:
-- 3 mg is 1/4 of 12 mg.
-- 1/4 is the product of (1/2) x (1/2).
-- So the 3 mg is what's left of 12 mg after 2 half-lives.
The 26 minutes must be two half-lives.
-- The half-life of that substance is 26/2 = <em>13 minutes</em>.
Go Maggie !
Answer:
wait.. almost done...
Step-by-step explanation:
Answer:
$1.20
Step-by-step explanation:
Ratio:
Grams : Kilograms
1 : .001
Multiply both sides by 20 to convert grams to kilograms:
Grams : Kilograms
1 : .001
x20 x20
20 : .02
This means that 20 grams of lead = .02 kilograms of lead
Price:
Cost : Kilogram
$60 : 1
Multiply both sides by .02 to find the price of the lead:
Cost : Kilogram
$60 : 1
x.02 x.02
$1.20 : .02
Therefore, .02 kg of lead costs $1.20.
