Water lillies double in area every 24 hour. In spring there is one water lily on a lake. In sixty days, the lake is completely covered with lillies. how many days did it take to cover half the lake

Answer 1

1 2 4 8 16
1 2^1 2^2 2^3 2^(n-1)
a a2^1 a 2^2 ....
geometric sequence with
a = 1
r = 2
n = number of days

2^59 = area

2^x = 2^59/2
x = n-1 = 58 so 59 days
which we could have said right off
because if you cover the whole lake in 60 days then the day before you must have half the lake covered.

Answer 2

Answer 58

Answer 3

Anish is right