day one: 750 * 1 = 750
day two: 750 * 3 = 2250
day three: 2250 * 3 = 6750
day four: 6750 * 3 = 20250
day five: 20250 * 3 = 60750
day six: 60750 * 3 = 182250
add it all together: 750 + 2250 + 6750 + 20250 + 60750 + 182250 = 273000
The answer is C, 273000.