If I am correct it should be the second one
Answer:

Step-by-step explanation:
We want to find the square root of 50;
We need to first rewrite 50 as a prime factorization.

We now split the square root to get:

Take square root to get:


To the nearest tenth we have 
Answer:
48 km/h
Step-by-step explanation:
80/50*30=48 km/h