What a lot of Maths!
Once you've finished this quiz, you'll be more familiar with the future perfect tense.
Not every language probably bothers with this, but it makes useful sense to have a tense that reaches forward to a point in the future and expresses what 'will have been done' by the time that moment arrives. There may well also be an element of the Continuous in it. 'Once you've finished' with this Quiz, you'll be a 'dab hand' at establishing deadlines on your future plans!
(A typical human scalp contains up to 120,000 follicles, each growing up to 1cm/month, which yields an annual total of almost 15km; multiply that by 11 years, and you have 100 miles or so of hair!)
Meanwhle, the tenses in Answers 1 & 2 are understandable but wrong; there was no need for a Conditional in Answer 4.