I need to know what the average speed of the swimmer was

1.5 units^2

Step-by-step explanation:

The average speed of the swimmer=

Total distance/ total time

Total distance = 15+30+45+60

= 150

Total time = 10+20+30+40

= 100

So the average speed will be

150/100

= 1.5 units^2

Another method is that is d is 1.5t

Speed is

1.5t/t

= 1.5

aloha~! my name is zalgo and i am here to you out on this amazing day. to answer your question, yes, nonzero numbers can have a greatest common factor and that would be 1. still don't get it? let me considering every number is divisible by 1 and hence every number has 1 as a factor of theirs. so, if 2 nonzero numbers didn't share any gcf (greatest common factor), they would still have a factor in common and that would be 1.

i hope that this ! : p

"stay and stay proud! " - zalgo

(by the way, do you mind marking me as brainliest? i'd greatly appreciate it! mahalo! x3)