There are n ill-behaved children named 1, 2, · · · , n. You are given a bunch of statements of the form "i throws rocks at j". Your goal is to arrange the kids into rows such that if i throws rocks at j then i must be in a lower numbered row than j. Give an algorithm to find the minimum number of rows needed, if it is possible.

a)

$4,000 + $960 = $4,960

She has $4,960 in her account at the end of 3 years

b)

i = Prt

r = i/Pt

r = 960 / 4000 * 3

r = 960 / 12000

r = 0.08

Annual interest rate is 0.08 or 8%

c) If 1% greater then r = 0.09 (9%)

i = Prt

i = $4,000 * 0.09 * 3

i = $1, 080

The different: $1, 080 - $960 = $120

She would have $120 more in her account if the interest rate were 1% greater.