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
It can be written as √64·√x¹⁶ = 8x⁸, so answer B.
Answer:
First one is 25/2
Step-by-step explanation:
12×2+1=25/2
9×4+1=36/4
cross multiply and you get
100/
divide both by 2 and you get 50/4 then you divide both by 2 again and you get 25/2 because you can't reduce it anymore
Answer:

Step-by-step explanation:
First we calculate the number of possible ways to select 2 cards an ace and a card of 10 points.
There are 4 ace in the deck
There are 16 cards of 10 points in the deck
To make this calculation we use the formula of combinations

Where n is the total number of letters and r are chosen from them
The number of ways to choose 1 As is:

The number of ways to choose a 10-point letter is:

Therefore, the number of ways to choose an Ace and a 10-point card is:

Now the number of ways to choose any 2 cards from a deck of 52 cards is:


Therefore, the probability of obtaining an "blackjack" is:




