Answer:
0.4
Step-by-step explanation:
Radius of inner circle = r
Radius of entire circle = r + r + r + r + r = 5r
Probability that an arrow hitting the target will land on inner circle ;
Area of inner circle / area of entire circle
Recall :
Area of circle = πr²
Hence ;
πr² / π(5r)²  = πr² / π25r² = 1 / 25 = 0.4