First, we know it can't be median because 72 is not a value in the data. If you find the mean/average, you will find that it is 72 ANSWER: Mean/average
Let d be distance travelled when they are level , and t = time that nora took to get level with mason
for Nora
6 = d/t
d = 6t
for Mason
5 = d / (t + 35)
d = 5 ( t + 350
so 6t = 5(t + 35)
solve for t