Please help I don't understand​

Answer:
3. 3:5
4. 4:1
Step-by-step explanation:
Just ratios I believe, myb if it's wrong but that should be it.
Since 3 & 5 aren't divisible by anything the scale factor is just 3:5.
Since 24 & 6 are divisible by a common number, being 6, you'd divide 24:6 & get a scale factor of 4:1.