Answer:
n ≥ 8
Step-by-step explanation:
Let R and E stand for the number of cows owned by Richard and Ellis, respectively.
We are told that:
R = n
E = 4n
Then:
R = n+13 [Bought 13 cows]
and
E = 4n-9 [Sold 9 cows]
Still:
E > R [Ellis still has more cows]
Therefore:
4n-9 > n+13
3n > 22
n > 7 1/3
Since no rancher wants 1/3 of a cow, we need to round either up or down to a whole number. The least value of n is therefore 8 cows or higher. Since 8 is a valid number, change the > inequality to ≥.
n ≥ 8
