Question

The seed of a particular variety of Rose in a Rose garden at Lalbagh, multiplies into two everyday due to reproduction. If there is only one seed on the first day, it increases to two on the second day, increases to four on the third day, increases to eight on the fourth day and so on. If starting with one seed, it takes 30 days to cover 200 square meters plot, how long will it take to cover the same plot if started with two seeds?

• A. 16 days
• B. 29 days
• C. 15 days
• D. 17 days

Answer 1

The correct option is B 29 days

$Totalseedsrequired=1\ast \frac{(2^{30}-1)}{2-1}\left[Sumofageometricseries\right)When2seedsarethere:(2^{30}-1)=2\ast \frac{(2^n-1)}{2-1}Clearly29>n>28Henceweneed29days$