Answer:
v=4pi r^2
if d=6x so r=3x
v=4pi(3x)^2
c is answer
Step-by-step explanation:
CP of ring = 1200
profit % = 15%
Profit amount = 15% 0f 1200 = 180
SP = 1200 + 180 = 1380
pi/4
my answer is in the image above