The last one would be incorrect. We are looking for PART of whatever N is. Multiply by the whole number 25 is definitely not what we want to do.
Hope I helped!
Answer:
First find the circumference by pi r squared.
Answer:
m/(1 - .8)
Step-by-step explanation:
She read 80% of her emails, which is .8 of the total. So her unread emails would be 100% - 80% = 1 - .8
that means me can be written as:
m = (1 - .8)t
where t is the total
If we solve for t, we get:
t = m/(1 - .8)

bearing in mind that, the geometric sequence is "convergent" only when |r|<1, or namely "r" is a fraction between 0 and 1.