Among smartphone users, 40% use a case but no screen protector, 10% use a screen protector but no case, 45% use both a case and a screen protector, and 5% use neither a case nor a screen protector. Twenty smartphone users are sampled at random. Let X1, X2, X3, X4 be the respective numbers of users in the four given categories.

Find P(X1=7, X2=3, X3=8, X4=2).

30 people weigh 160 pounds or more

step-by-step explanation:

we can use this expression to calculate the energy gain as a particle moves with a field or the energy loss as it moves against it. (note that it is also used to define the electron-volt, a unit of energy equal to that gained by an electron as it falls through a pd of 1 v, i.e. w = 1 ev = 1.6 10-19 c 1 v = 1.6 10-19j).in fact this expression is really nothing more than the statement that potential is the potential energy per unit charge. in this case, v= w/qis simply stating that the change in potential energy(or work done) per unit charge is equal to the change in potential (or potential difference), v.student questions: uniform electric fields2electron beamcathode+5 kvanode0 v

the answer should be:

a. 3, 4, and 6

b. 18, 24, and 36

c. 4.8, 6.4, and 9.6

hope i

-lavira : )

the answer is a and d