Answer: 5 treadmills : 6 elliptical machines.
Explanation:
We know that , the ratio of A to B can be written as :
or A : B.
As per the question , we need to find the ratio of 30 treadmills to 36 elliptical machines, which can be written as

Since , the numerator and denominator are multiple of 6, so we divide both of them by 6, we get

That is the require ratio is 5 treadmills : 6 elliptical machines.