Let XXX and YYY be independent Exponential(λ=1)\text{Exponential}(\lambda = 1)Exponential(λ=1). What is P(X+Y<2)P(X + Y < 2)P(X+Y<2)?
1−3e−21 - 3e^{-2}1−3e−2
1−e−21 - e^{-2}1−e−2
e−2e^{-2}e−2
3e−23e^{-2}3e−2