Answer:
1/26
Step-by-step explanation:
There are 4 Jacks in every deck of cards, one for each suit. Therefore your chances of drawing a Jack, or any other card for that matter, are 4 in 52. So, the first probability for cards is 4/52.
Now, for the coin, the probability is 1/2.
So, the probability of getting Jack and hits is 4/52 X 1/2 = 1/26.
15
Step-by-step explanation:
A negative number being subtracted makes it positive
5 - -10
5+10 =15
Answer:
No
Step-by-step explanation:
Using this method, each group of 60 players do not have the same chance of being selected.
Also with this method, the selection will not be uniformly distributed among the 30 teams. Some teams will have more players, some will have few and some will have no player selected at all.
1.326 grams of NH3 are required to produce 4.65 g of HF.
Step-by-step explanation:
Balanced chemical reaction is written first to know the number of moles taking part in original reaction.
NH3 +3 F2 ⇒3 HF + NF3
Given:
mass of HF = 4.65
First the number of moles of HF in 4.65 grams is calculated by using the formula:
number of moles (n) = 
atomic mass of HF = 20 grams/mole
putting the values in the above equation number of moles can be found.
n = 
= 0.235 moles of HF are given.
From the equation it can be said that:
1 mole of NH3 reacts to form 3 moles of HF
so, x moles of NH3 would react to form 0.235 moles of HF
= 
3x = 0.235
x = 
x = 0.078 moles of NH3 is required.
The moles are converted to mass by applying the formula:
mass = atomic mass X number of moles (atomic mass of NH3 = 17 grams/mole)
putting the values in the formula
mass = 17 X 0.078
mass = 1.326 grams
The answer to this is x = 2