Assume that you have a binomial experiment with p=0.4 and a sample size of 100. the expected value for this binomial distribution is

In Binomial distribution, the expected value or mean is given by,
E(X) = np 
where, p = probability of success and n=number of sample size.

E(X) = 100×0.4 = 40 

Num of plants = (original#ofplants)*(1.6)^t