Answer:
Its C and there are 6 purple balloons hope this helps :)
Step-by-step explanation:
3x + 5 = 35
3x = 30
x = 10
3% is the interest so you would do 3% of the investment plus the original investment so 3%×I=z and then z+I=the answer. sorry if this didnt help I'm new and I tried my best sorry!