Consider a series system of 2 components. For the first component, there is only one device available, whose lifetime distribution is exponential with MTTF (mean time to failure) of 3 month. Meanwhile, for the second component, in addition to the working device there is also a spare one. Assume that lifetimes of these two devices devices exponentially distributed with the expected lifetime of 2 months, and that lifetimes of all three devices are independent random variables. (a) Find the reliability function of the system. (b) Find the system's MTTF. (c) Is the system IFR, DFR, or neither? Consider a series system of 2 components. For the first component, there is only one device available, whose lifetime distribution is exponential with MTTF (mean time to failure) of 3 month. Meanwhile, for the second component, in addition to the working device there is also a spare one. Assume that lifetimes of these two devices devices exponentially distributed with the expected lifetime of 2 months, and that lifetimes of all three devices are independent random variables. (a) Find the reliability function of the system. (b) Find the system's MTTF. (c) Is the system IFR, DFR, or neither