Answer: 405
Explanation:
ratio r for the geometric sequence: 5, 15, 45, 135
r is a radios of a circle,
d is the Diameter
r1=5. r2=15, r3=45, r4=135, r5=?
2*r=d
so:
d1=10, d2=30, d3=90, d4= 270
now following the sequence:
r1+d1=r2 5+10=15
r2+d2=r3 15+30=45
r3+d3=r4 45+90=135
r4+d4=r5 therefore 135 + (135*2) = 135+270=405