800 at 4.25% simple interst for 6 years

Mo = initial money
M  = my current money $_$ ( the more the better)
I   = interest rate <3
t   = time

t = 6

I = 4.25/100  ( I assume you mean per year)

Mo = 800 ( I assume you mean initial money)

M = Mo+ Mo (I) * t
 
M = 800 + 800(4.25/100) * 6= 1004 

Step-by-step explanation:

given that on a six-question multiple-choice test there are five possible answers for each question, of which one is correct and four are incorrect

By mere guessing probability for choosing correct answer = p = 0.2

also each question is independent of the other

Hence if X is the number of correct questions then

X is binomial with p = 0.2 and n = 6

a) being correct on three questions,

=

(b) being correct on four questions,

=

(c) being correct on all six questions

=