He will take 50 minutes.
To complete it’ll be 100%.
So if you multiple 20 times 2 it’ll give you 40…which will now have you at 80% So you need 20% left which is half of 40% to complete the 100% which will be half of 20 which is 10. Then you add to the 40 you alr have which sum up to 50min total!!!
