Question

I don't understand what this question is implying. . The number of cells increased 160 percent. If the original number was 800, what was the final
number?

Answer 1

Yes, it is a bit vague. If it had said "increased by 160%" then that would mean that 160% (or 1.6 times) the original amount was added, making the final population 800 + 1.6*800 = 2080

But maybe they meant that it "increased to" 160% of its current value, making the final value 1.6 * 800 = 1280

In general, though, I'd go with the first reading. If someone says that their money increased 100%, it means that it doubled (added 100%).

Answer 2

Thanks, oobleck!