Weights of elephants approximately follow an exponential distribution with the mean of 2.5 tons. One hundred elephants are being transported on a ship that has a cargo limit of 300 tons. What is the chance this ship will sink?

I think i kind of understand this problem but unsure.

lambda = 1/2.5 = 0.40

exp. dist. x < 300

so 1- e^-(0.40)(100) = 1 so it will sink?