If I have a wetland divided in 10 regions, and the probability to find another type of toad in any region is 0.3.

I calculated the density function like this:

n <- 10 #regions

p <- 0.3

X <- 0:n

densPr<- dbinom (X, n, p)

But I have some doubt in how I can calculate the (a)and (b) using less than or 4-8

(a) probability to find less than 6 regions with the toad and (b) probability to find 4 – 8 regions (inclusive) with the toad.