Hello!
Since we know how much they walked in 4/9 of an hour, we will divide 4/5 by 4/9 to get 4/9 to one.

÷

=

They went 1 4/5 mph or
1.8 mph.
I hope this helps!
A prime number<span> has only two factors: 1 and itself. A</span>composite number<span> has more than two factors. The</span>number<span> 1 is neither </span>prime<span> nor </span>composite<span>. The </span>prime numbers<span> between 2 and 31 are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 and 31 since each of these </span>numbers<span> has only two factors, itself and 1.</span>